diff --git a/.github/actions/setup-test-jdk/action.yml b/.github/actions/setup-test-jdk/action.yml
index 2aeb7c4f90f4..0d1099c45967 100644
--- a/.github/actions/setup-test-jdk/action.yml
+++ b/.github/actions/setup-test-jdk/action.yml
@@ -15,3 +15,10 @@ runs:
         check-latest: true
     - shell: bash
       run: echo "JDK8=$JAVA_HOME" >> $GITHUB_ENV
+    - uses: actions/setup-java@7a6d8a8234af8eb26422e24e3006232cccaa061b # v4
+      with:
+        distribution: ${{ inputs.distribution }}
+        java-version: 17
+        check-latest: true
+    - shell: bash
+      run: echo "JDK17=$JAVA_HOME" >> $GITHUB_ENV
diff --git a/documentation/documentation.gradle.kts b/documentation/documentation.gradle.kts
index 02c96f3035fc..068168209508 100644
--- a/documentation/documentation.gradle.kts
+++ b/documentation/documentation.gradle.kts
@@ -26,8 +26,8 @@ val modularProjects: List<Project> by rootProject
 modularProjects.forEach { evaluationDependsOn(it.path) }
 
 javaLibrary {
-	mainJavaVersion = JavaVersion.VERSION_1_8
-	testJavaVersion = JavaVersion.VERSION_1_8
+	mainJavaVersion = JavaVersion.VERSION_17
+	testJavaVersion = JavaVersion.VERSION_17
 }
 
 val apiReport = configurations.dependencyScope("apiReport")
diff --git a/gradle.properties b/gradle.properties
index 4f2ab7df9946..f95f4713c831 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -20,7 +20,7 @@ org.gradle.jvmargs=-Xmx1g -XX:MaxMetaspaceSize=512m -XX:+HeapDumpOnOutOfMemoryEr
 org.gradle.caching=true
 org.gradle.parallel=true
 org.gradle.configuration-cache.parallel=true
-org.gradle.java.installations.fromEnv=JDK8,JDK18,JDK19,JDK20,JDK21,JDK22,JDK23,JDK24
+org.gradle.java.installations.fromEnv=JDK8,JDK17,JDK21,JDK23,JDK24,JDK25
 org.gradle.kotlin.dsl.allWarningsAsErrors=true
 
 # Test Distribution
diff --git a/gradle/plugins/common/src/main/kotlin/JavaLibraryExtension.kt b/gradle/plugins/common/src/main/kotlin/JavaLibraryExtension.kt
index 64a61da7fb7b..9cc28076bbc4 100644
--- a/gradle/plugins/common/src/main/kotlin/JavaLibraryExtension.kt
+++ b/gradle/plugins/common/src/main/kotlin/JavaLibraryExtension.kt
@@ -1,7 +1,7 @@
 import org.gradle.api.JavaVersion
 
 open class JavaLibraryExtension {
-    var mainJavaVersion: JavaVersion = JavaVersion.VERSION_1_8
+    var mainJavaVersion: JavaVersion = JavaVersion.VERSION_17
     var testJavaVersion: JavaVersion = JavaVersion.VERSION_21
     var configureRelease: Boolean = true
 }
diff --git a/gradle/plugins/common/src/main/kotlin/junitbuild.java-library-conventions.gradle.kts b/gradle/plugins/common/src/main/kotlin/junitbuild.java-library-conventions.gradle.kts
index b14973e05474..96b3b1b06bbc 100644
--- a/gradle/plugins/common/src/main/kotlin/junitbuild.java-library-conventions.gradle.kts
+++ b/gradle/plugins/common/src/main/kotlin/junitbuild.java-library-conventions.gradle.kts
@@ -184,10 +184,8 @@ val compileModule by tasks.registering(JavaCompile::class) {
 	enabled = project in modularProjects
 	source = fileTree(combinedModuleSourceDir).builtBy(prepareModuleSourceDir)
 	destinationDirectory = moduleOutputDir
-	sourceCompatibility = "9"
-	targetCompatibility = "9"
 	classpath = files()
-	options.release = 9
+	options.release = 17
 	options.compilerArgs.addAll(listOf(
 			// Suppress warnings for automatic modules: org.apiguardian.api, org.opentest4j
 			"-Xlint:all,-requires-automatic,-requires-transitive-automatic",
@@ -262,17 +260,14 @@ tasks.withType<JavaCompile>().configureEach {
 }
 
 tasks.compileJava {
-	// See: https://docs.oracle.com/en/java/javase/12/tools/javac.html
 	options.compilerArgs.addAll(listOf(
 			"-Xlint:all", // Enables all recommended warnings.
 			"-Werror", // Terminates compilation when warnings occur.
-			// Required for compatibility with Java 8's reflection APIs (see https://github.com/junit-team/junit5/issues/3797).
 			"-parameters", // Generates metadata for reflection on method parameters.
 	))
 }
 
 tasks.compileTestJava {
-	// See: https://docs.oracle.com/en/java/javase/12/tools/javac.html
 	options.compilerArgs.addAll(listOf(
 			"-Xlint", // Enables all recommended warnings.
 			"-Xlint:-overrides", // Disables "method overrides" warnings.
diff --git a/gradle/plugins/common/src/main/kotlin/junitbuild.java-multi-release-sources.gradle.kts b/gradle/plugins/common/src/main/kotlin/junitbuild.java-multi-release-sources.gradle.kts
deleted file mode 100644
index 83b2a8e8e273..000000000000
--- a/gradle/plugins/common/src/main/kotlin/junitbuild.java-multi-release-sources.gradle.kts
+++ /dev/null
@@ -1,45 +0,0 @@
-import junitbuild.extensions.capitalized
-
-plugins {
-	id("junitbuild.java-library-conventions")
-}
-
-val mavenizedProjects: List<Project> by rootProject.extra
-
-listOf(9, 17).forEach { javaVersion ->
-	val sourceSet = sourceSets.register("mainRelease${javaVersion}") {
-		compileClasspath += sourceSets.main.get().output
-		runtimeClasspath += sourceSets.main.get().output
-		java {
-			setSrcDirs(setOf("src/main/java${javaVersion}"))
-		}
-	}
-
-	configurations.named(sourceSet.get().compileClasspathConfigurationName).configure {
-		extendsFrom(configurations.compileClasspath.get())
-	}
-
-	tasks {
-
-		named("allMainClasses").configure {
-			dependsOn(sourceSet.get().classesTaskName)
-		}
-
-		named<JavaCompile>(sourceSet.get().compileJavaTaskName).configure {
-			options.release = javaVersion
-		}
-
-		named<Checkstyle>("checkstyle${sourceSet.name.capitalized()}").configure {
-			config = resources.text.fromFile(checkstyle.configDirectory.file("checkstyleMain.xml"))
-		}
-
-		if (project in mavenizedProjects) {
-			javadoc {
-				source(sourceSet.get().allJava)
-			}
-			named<Jar>("sourcesJar").configure {
-				from(sourceSet.get().allSource)
-			}
-		}
-	}
-}
diff --git a/junit-platform-commons/junit-platform-commons.gradle.kts b/junit-platform-commons/junit-platform-commons.gradle.kts
index 3de45a7edfee..eba72705cce1 100644
--- a/junit-platform-commons/junit-platform-commons.gradle.kts
+++ b/junit-platform-commons/junit-platform-commons.gradle.kts
@@ -1,8 +1,5 @@
-import junitbuild.java.UpdateJarAction
-
 plugins {
 	id("junitbuild.java-library-conventions")
-	id("junitbuild.java-multi-release-sources")
 	id("junitbuild.native-image-properties")
 	`java-test-fixtures`
 }
@@ -14,28 +11,3 @@ dependencies {
 
 	compileOnlyApi(libs.apiguardian)
 }
-
-tasks.jar {
-	val release9ClassesDir = sourceSets.mainRelease9.get().output.classesDirs.singleFile
-	inputs.dir(release9ClassesDir).withPathSensitivity(PathSensitivity.RELATIVE)
-	doLast(objects.newInstance(UpdateJarAction::class).apply {
-		javaLauncher = javaToolchains.launcherFor(java.toolchain)
-		args.addAll(
-			"--file", archiveFile.get().asFile.absolutePath,
-			"--release", "9",
-			"-C", release9ClassesDir.absolutePath, "."
-		)
-	})
-}
-
-tasks.codeCoverageClassesJar {
-	exclude("org/junit/platform/commons/util/ModuleUtils.class")
-	exclude("org/junit/platform/commons/util/PackageNameUtils.class")
-	exclude("org/junit/platform/commons/util/ServiceLoaderUtils.class")
-}
-
-eclipse {
-	classpath {
-		sourceSets -= project.sourceSets.mainRelease9.get()
-	}
-}
diff --git a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/ModuleUtils.java b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/ModuleUtils.java
index 980c06394ea2..9f20d964f471 100644
--- a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/ModuleUtils.java
+++ b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/ModuleUtils.java
@@ -10,18 +10,34 @@
 
 package org.junit.platform.commons.util;
 
-import static java.util.Collections.emptyList;
-import static java.util.Collections.emptySet;
+import static java.util.function.Predicate.isEqual;
+import static java.util.stream.Collectors.toCollection;
+import static java.util.stream.Collectors.toSet;
 import static org.apiguardian.api.API.Status.INTERNAL;
 
+import java.io.IOException;
+import java.lang.module.Configuration;
+import java.lang.module.ModuleFinder;
+import java.lang.module.ModuleReader;
+import java.lang.module.ModuleReference;
+import java.lang.module.ResolvedModule;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.apiguardian.api.API;
+import org.junit.platform.commons.JUnitException;
 import org.junit.platform.commons.logging.Logger;
 import org.junit.platform.commons.logging.LoggerFactory;
+import org.junit.platform.commons.support.DefaultResource;
 import org.junit.platform.commons.support.Resource;
 import org.junit.platform.commons.support.scanning.ClassFilter;
 
@@ -49,42 +65,40 @@ public class ModuleUtils {
 	 * potentially empty
 	 */
 	public static Set<String> findAllNonSystemBootModuleNames() {
-		logger.config(() -> "Basic version of findAllNonSystemBootModuleNames() always returns an empty set!");
-		return emptySet();
+		// @formatter:off
+		Set<String> systemModules = ModuleFinder.ofSystem().findAll().stream()
+				.map(reference -> reference.descriptor().name())
+				.collect(toSet());
+		return streamResolvedModules(name -> !systemModules.contains(name))
+				.map(ResolvedModule::name)
+				.collect(toCollection(LinkedHashSet::new));
+		// @formatter:on
 	}
 
 	/**
-	 * Determine if the current Java runtime supports the Java Platform Module System.
+	 * Java 9+ runtime supports the Java Platform Module System.
 	 *
-	 * @return {@code true} if the Java Platform Module System is available,
-	 * otherwise {@code false}
+	 * @return {@code true}
 	 */
 	public static boolean isJavaPlatformModuleSystemAvailable() {
-		return false;
+		return true;
 	}
 
-	/**
-	 * Return the name of the module that the class or interface is a member of.
-	 *
-	 * @param type class or interface to analyze
-	 * @return the module name; never {@code null} but potentially empty
-	 */
 	public static Optional<String> getModuleName(Class<?> type) {
-		return Optional.empty();
+		Preconditions.notNull(type, "Class type must not be null");
+
+		return Optional.ofNullable(type.getModule().getName());
 	}
 
-	/**
-	 * Return the raw version of the module that the class or interface is a member of.
-	 *
-	 * @param type class or interface to analyze
-	 * @return the raw module version; never {@code null} but potentially empty
-	 */
 	public static Optional<String> getModuleVersion(Class<?> type) {
-		return Optional.empty();
+		Preconditions.notNull(type, "Class type must not be null");
+
+		Module module = type.getModule();
+		return module.isNamed() ? module.getDescriptor().rawVersion() : Optional.empty();
 	}
 
 	/**
-	 * Find all classes for the given module name.
+	 * Find all {@linkplain Class classes} for the given module name.
 	 *
 	 * @param moduleName the name of the module to scan; never {@code null} or
 	 * <em>empty</em>
@@ -96,12 +110,17 @@ public static List<Class<?>> findAllClassesInModule(String moduleName, ClassFilt
 		Preconditions.notBlank(moduleName, "Module name must not be null or empty");
 		Preconditions.notNull(filter, "Class filter must not be null");
 
-		logger.config(() -> "Basic version of findAllClassesInModule() always returns an empty list!");
-		return emptyList();
+		logger.debug(() -> "Looking for classes in module: " + moduleName);
+		// @formatter:off
+		Set<ModuleReference> moduleReferences = streamResolvedModules(isEqual(moduleName))
+				.map(ResolvedModule::reference)
+				.collect(toSet());
+		// @formatter:on
+		return scan(moduleReferences, filter, ModuleUtils.class.getClassLoader());
 	}
 
 	/**
-	 * Find all resources for the given module name.
+	 * Find all {@linkplain Resource resources} for the given module name.
 	 *
 	 * @param moduleName the name of the module to scan; never {@code null} or
 	 * <em>empty</em>
@@ -115,8 +134,178 @@ public static List<Resource> findAllResourcesInModule(String moduleName, Predica
 		Preconditions.notBlank(moduleName, "Module name must not be null or empty");
 		Preconditions.notNull(filter, "Resource filter must not be null");
 
-		logger.config(() -> "Basic version of findAllResourcesInModule() always returns an empty list!");
-		return emptyList();
+		logger.debug(() -> "Looking for classes in module: " + moduleName);
+		// @formatter:off
+		Set<ModuleReference> moduleReferences = streamResolvedModules(isEqual(moduleName))
+				.map(ResolvedModule::reference)
+				.collect(toSet());
+		// @formatter:on
+		return scan(moduleReferences, filter, ModuleUtils.class.getClassLoader());
+	}
+
+	/**
+	 * Stream resolved modules from current (or boot) module layer.
+	 */
+	private static Stream<ResolvedModule> streamResolvedModules(Predicate<String> moduleNamePredicate) {
+		Module module = ModuleUtils.class.getModule();
+		ModuleLayer layer = module.getLayer();
+		if (layer == null) {
+			logger.config(() -> ModuleUtils.class + " is a member of " + module
+					+ " - using boot layer returned by ModuleLayer.boot() as fall-back.");
+			layer = ModuleLayer.boot();
+		}
+		return streamResolvedModules(moduleNamePredicate, layer);
+	}
+
+	/**
+	 * Stream resolved modules from the supplied layer.
+	 */
+	private static Stream<ResolvedModule> streamResolvedModules(Predicate<String> moduleNamePredicate,
+			ModuleLayer layer) {
+		logger.debug(() -> "Streaming modules for layer @" + System.identityHashCode(layer) + ": " + layer);
+		Configuration configuration = layer.configuration();
+		logger.debug(() -> "Module layer configuration: " + configuration);
+		Stream<ResolvedModule> stream = configuration.modules().stream();
+		return stream.filter(module -> moduleNamePredicate.test(module.name()));
+	}
+
+	/**
+	 * Scan for classes using the supplied set of module references, class
+	 * filter, and loader.
+	 */
+	private static List<Class<?>> scan(Set<ModuleReference> references, ClassFilter filter, ClassLoader loader) {
+		logger.debug(() -> "Scanning " + references.size() + " module references: " + references);
+		ModuleReferenceClassScanner scanner = new ModuleReferenceClassScanner(filter, loader);
+		List<Class<?>> classes = new ArrayList<>();
+		for (ModuleReference reference : references) {
+			classes.addAll(scanner.scan(reference));
+		}
+		logger.debug(() -> "Found " + classes.size() + " classes: " + classes);
+		return Collections.unmodifiableList(classes);
+	}
+
+	/**
+	 * Scan for classes using the supplied set of module references, class
+	 * filter, and loader.
+	 */
+	private static List<Resource> scan(Set<ModuleReference> references, Predicate<Resource> filter,
+			ClassLoader loader) {
+		logger.debug(() -> "Scanning " + references.size() + " module references: " + references);
+		ModuleReferenceResourceScanner scanner = new ModuleReferenceResourceScanner(filter, loader);
+		List<Resource> classes = new ArrayList<>();
+		for (ModuleReference reference : references) {
+			classes.addAll(scanner.scan(reference));
+		}
+		logger.debug(() -> "Found " + classes.size() + " classes: " + classes);
+		return Collections.unmodifiableList(classes);
+	}
+
+	/**
+	 * {@link ModuleReference} class scanner.
+	 *
+	 * @since 1.1
+	 */
+	static class ModuleReferenceClassScanner {
+
+		private final ClassFilter classFilter;
+		private final ClassLoader classLoader;
+
+		ModuleReferenceClassScanner(ClassFilter classFilter, ClassLoader classLoader) {
+			this.classFilter = classFilter;
+			this.classLoader = classLoader;
+		}
+
+		/**
+		 * Scan module reference for classes that potentially contain testable methods.
+		 */
+		List<Class<?>> scan(ModuleReference reference) {
+			try (ModuleReader reader = reference.open()) {
+				try (Stream<String> names = reader.list()) {
+					// @formatter:off
+					return names.filter(name -> name.endsWith(".class"))
+							.map(this::className)
+							.filter(name -> !name.equals("module-info"))
+							.filter(classFilter::match)
+							.map(this::loadClassUnchecked)
+							.filter(classFilter::match)
+							.collect(Collectors.toList());
+					// @formatter:on
+				}
+			}
+			catch (IOException e) {
+				throw new JUnitException("Failed to read contents of " + reference + ".", e);
+			}
+		}
+
+		/**
+		 * Convert resource name to binary class name.
+		 */
+		private String className(String resourceName) {
+			resourceName = resourceName.substring(0, resourceName.length() - 6); // 6 = ".class".length()
+			resourceName = resourceName.replace('/', '.');
+			return resourceName;
+		}
+
+		/**
+		 * Load class by its binary name.
+		 *
+		 * @see ClassLoader#loadClass(String)
+		 */
+		private Class<?> loadClassUnchecked(String binaryName) {
+			try {
+				return classLoader.loadClass(binaryName);
+			}
+			catch (ClassNotFoundException e) {
+				throw new JUnitException("Failed to load class with name '" + binaryName + "'.", e);
+			}
+		}
+
+	}
+
+	/**
+	 * {@link ModuleReference} resource class scanner.
+	 *
+	 * @since 1.11
+	 */
+	static class ModuleReferenceResourceScanner {
+
+		private final Predicate<Resource> resourceFilter;
+		private final ClassLoader classLoader;
+
+		ModuleReferenceResourceScanner(Predicate<Resource> resourceFilter, ClassLoader classLoader) {
+			this.resourceFilter = resourceFilter;
+			this.classLoader = classLoader;
+		}
+
+		/**
+		 * Scan module reference for resources that potentially contain testable resources.
+		 */
+		List<Resource> scan(ModuleReference reference) {
+			try (ModuleReader reader = reference.open()) {
+				try (Stream<String> names = reader.list()) {
+					// @formatter:off
+					return names.filter(name -> !name.endsWith(".class"))
+							.map(this::loadResourceUnchecked)
+							.filter(resourceFilter)
+							.collect(Collectors.toList());
+					// @formatter:on
+				}
+			}
+			catch (IOException e) {
+				throw new JUnitException("Failed to read contents of " + reference + ".", e);
+			}
+		}
+
+		private Resource loadResourceUnchecked(String binaryName) {
+			try {
+				URI uri = classLoader.getResource(binaryName).toURI();
+				return new DefaultResource(binaryName, uri);
+			}
+			catch (URISyntaxException e) {
+				throw new JUnitException("Failed to load resource with name '" + binaryName + "'.", e);
+			}
+		}
+
 	}
 
 }
diff --git a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/PackageNameUtils.java b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/PackageNameUtils.java
index 2a0094dda4c4..0cb6aec9e8d8 100644
--- a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/PackageNameUtils.java
+++ b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/PackageNameUtils.java
@@ -10,8 +10,6 @@
 
 package org.junit.platform.commons.util;
 
-import static org.junit.platform.commons.util.PackageUtils.DEFAULT_PACKAGE_NAME;
-
 /**
  * Collection of utilities for working with package names.
  *
@@ -26,13 +24,7 @@
 class PackageNameUtils {
 
 	static String getPackageName(Class<?> clazz) {
-		Package p = clazz.getPackage();
-		if (p != null) {
-			return p.getName();
-		}
-		String className = clazz.getName();
-		int index = className.lastIndexOf('.');
-		return index == -1 ? DEFAULT_PACKAGE_NAME : className.substring(0, index);
+		return clazz.getPackageName();
 	}
 
 }
diff --git a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/ServiceLoaderUtils.java b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/ServiceLoaderUtils.java
index ce006d770099..878c62a2c7e7 100644
--- a/junit-platform-commons/src/main/java/org/junit/platform/commons/util/ServiceLoaderUtils.java
+++ b/junit-platform-commons/src/main/java/org/junit/platform/commons/util/ServiceLoaderUtils.java
@@ -13,9 +13,9 @@
 import java.util.ServiceLoader;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
-import java.util.stream.StreamSupport;
 
 import org.apiguardian.api.API;
+import org.apiguardian.api.API.Status;
 
 /**
  * Collection of utilities for working with {@link ServiceLoader}.
@@ -28,7 +28,7 @@
  *
  * @since 5.11
  */
-@API(status = API.Status.INTERNAL, since = "5.11")
+@API(status = Status.INTERNAL, since = "5.11")
 public class ServiceLoaderUtils {
 
 	private ServiceLoaderUtils() {
@@ -45,11 +45,12 @@ private ServiceLoaderUtils() {
 	 */
 	public static <T> Stream<T> filter(ServiceLoader<T> serviceLoader,
 			Predicate<? super Class<? extends T>> providerPredicate) {
-		return StreamSupport.stream(serviceLoader.spliterator(), false).filter(it -> {
-			@SuppressWarnings("unchecked")
-			Class<? extends T> type = (Class<? extends T>) it.getClass();
-			return providerPredicate.test(type);
-		});
+		// @formatter:off
+		return serviceLoader
+				.stream()
+				.filter(provider -> providerPredicate.test(provider.type()))
+				.map(ServiceLoader.Provider::get);
+		// @formatter:on
 	}
 
 }
diff --git a/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/ModuleUtils.java b/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/ModuleUtils.java
deleted file mode 100644
index 9f20d964f471..000000000000
--- a/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/ModuleUtils.java
+++ /dev/null
@@ -1,311 +0,0 @@
-/*
- * Copyright 2015-2025 the original author or authors.
- *
- * All rights reserved. This program and the accompanying materials are
- * made available under the terms of the Eclipse Public License v2.0 which
- * accompanies this distribution and is available at
- *
- * https://www.eclipse.org/legal/epl-v20.html
- */
-
-package org.junit.platform.commons.util;
-
-import static java.util.function.Predicate.isEqual;
-import static java.util.stream.Collectors.toCollection;
-import static java.util.stream.Collectors.toSet;
-import static org.apiguardian.api.API.Status.INTERNAL;
-
-import java.io.IOException;
-import java.lang.module.Configuration;
-import java.lang.module.ModuleFinder;
-import java.lang.module.ModuleReader;
-import java.lang.module.ModuleReference;
-import java.lang.module.ResolvedModule;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Optional;
-import java.util.Set;
-import java.util.function.Predicate;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
-import org.apiguardian.api.API;
-import org.junit.platform.commons.JUnitException;
-import org.junit.platform.commons.logging.Logger;
-import org.junit.platform.commons.logging.LoggerFactory;
-import org.junit.platform.commons.support.DefaultResource;
-import org.junit.platform.commons.support.Resource;
-import org.junit.platform.commons.support.scanning.ClassFilter;
-
-/**
- * Collection of utilities for working with {@code java.lang.Module}
- * and friends.
- *
- * <h2>DISCLAIMER</h2>
- *
- * <p>These utilities are intended solely for usage within the JUnit framework
- * itself. <strong>Any usage by external parties is not supported.</strong>
- * Use at your own risk!
- *
- * @since 1.1
- */
-@API(status = INTERNAL, since = "1.1")
-public class ModuleUtils {
-
-	private static final Logger logger = LoggerFactory.getLogger(ModuleUtils.class);
-
-	/**
-	 * Find all non-system boot modules names.
-	 *
-	 * @return a set of all such module names; never {@code null} but
-	 * potentially empty
-	 */
-	public static Set<String> findAllNonSystemBootModuleNames() {
-		// @formatter:off
-		Set<String> systemModules = ModuleFinder.ofSystem().findAll().stream()
-				.map(reference -> reference.descriptor().name())
-				.collect(toSet());
-		return streamResolvedModules(name -> !systemModules.contains(name))
-				.map(ResolvedModule::name)
-				.collect(toCollection(LinkedHashSet::new));
-		// @formatter:on
-	}
-
-	/**
-	 * Java 9+ runtime supports the Java Platform Module System.
-	 *
-	 * @return {@code true}
-	 */
-	public static boolean isJavaPlatformModuleSystemAvailable() {
-		return true;
-	}
-
-	public static Optional<String> getModuleName(Class<?> type) {
-		Preconditions.notNull(type, "Class type must not be null");
-
-		return Optional.ofNullable(type.getModule().getName());
-	}
-
-	public static Optional<String> getModuleVersion(Class<?> type) {
-		Preconditions.notNull(type, "Class type must not be null");
-
-		Module module = type.getModule();
-		return module.isNamed() ? module.getDescriptor().rawVersion() : Optional.empty();
-	}
-
-	/**
-	 * Find all {@linkplain Class classes} for the given module name.
-	 *
-	 * @param moduleName the name of the module to scan; never {@code null} or
-	 * <em>empty</em>
-	 * @param filter the class filter to apply; never {@code null}
-	 * @return an immutable list of all such classes found; never {@code null}
-	 * but potentially empty
-	 */
-	public static List<Class<?>> findAllClassesInModule(String moduleName, ClassFilter filter) {
-		Preconditions.notBlank(moduleName, "Module name must not be null or empty");
-		Preconditions.notNull(filter, "Class filter must not be null");
-
-		logger.debug(() -> "Looking for classes in module: " + moduleName);
-		// @formatter:off
-		Set<ModuleReference> moduleReferences = streamResolvedModules(isEqual(moduleName))
-				.map(ResolvedModule::reference)
-				.collect(toSet());
-		// @formatter:on
-		return scan(moduleReferences, filter, ModuleUtils.class.getClassLoader());
-	}
-
-	/**
-	 * Find all {@linkplain Resource resources} for the given module name.
-	 *
-	 * @param moduleName the name of the module to scan; never {@code null} or
-	 * <em>empty</em>
-	 * @param filter the class filter to apply; never {@code null}
-	 * @return an immutable list of all such resources found; never {@code null}
-	 * but potentially empty
-	 * @since 1.11
-	 */
-	@API(status = INTERNAL, since = "1.11")
-	public static List<Resource> findAllResourcesInModule(String moduleName, Predicate<Resource> filter) {
-		Preconditions.notBlank(moduleName, "Module name must not be null or empty");
-		Preconditions.notNull(filter, "Resource filter must not be null");
-
-		logger.debug(() -> "Looking for classes in module: " + moduleName);
-		// @formatter:off
-		Set<ModuleReference> moduleReferences = streamResolvedModules(isEqual(moduleName))
-				.map(ResolvedModule::reference)
-				.collect(toSet());
-		// @formatter:on
-		return scan(moduleReferences, filter, ModuleUtils.class.getClassLoader());
-	}
-
-	/**
-	 * Stream resolved modules from current (or boot) module layer.
-	 */
-	private static Stream<ResolvedModule> streamResolvedModules(Predicate<String> moduleNamePredicate) {
-		Module module = ModuleUtils.class.getModule();
-		ModuleLayer layer = module.getLayer();
-		if (layer == null) {
-			logger.config(() -> ModuleUtils.class + " is a member of " + module
-					+ " - using boot layer returned by ModuleLayer.boot() as fall-back.");
-			layer = ModuleLayer.boot();
-		}
-		return streamResolvedModules(moduleNamePredicate, layer);
-	}
-
-	/**
-	 * Stream resolved modules from the supplied layer.
-	 */
-	private static Stream<ResolvedModule> streamResolvedModules(Predicate<String> moduleNamePredicate,
-			ModuleLayer layer) {
-		logger.debug(() -> "Streaming modules for layer @" + System.identityHashCode(layer) + ": " + layer);
-		Configuration configuration = layer.configuration();
-		logger.debug(() -> "Module layer configuration: " + configuration);
-		Stream<ResolvedModule> stream = configuration.modules().stream();
-		return stream.filter(module -> moduleNamePredicate.test(module.name()));
-	}
-
-	/**
-	 * Scan for classes using the supplied set of module references, class
-	 * filter, and loader.
-	 */
-	private static List<Class<?>> scan(Set<ModuleReference> references, ClassFilter filter, ClassLoader loader) {
-		logger.debug(() -> "Scanning " + references.size() + " module references: " + references);
-		ModuleReferenceClassScanner scanner = new ModuleReferenceClassScanner(filter, loader);
-		List<Class<?>> classes = new ArrayList<>();
-		for (ModuleReference reference : references) {
-			classes.addAll(scanner.scan(reference));
-		}
-		logger.debug(() -> "Found " + classes.size() + " classes: " + classes);
-		return Collections.unmodifiableList(classes);
-	}
-
-	/**
-	 * Scan for classes using the supplied set of module references, class
-	 * filter, and loader.
-	 */
-	private static List<Resource> scan(Set<ModuleReference> references, Predicate<Resource> filter,
-			ClassLoader loader) {
-		logger.debug(() -> "Scanning " + references.size() + " module references: " + references);
-		ModuleReferenceResourceScanner scanner = new ModuleReferenceResourceScanner(filter, loader);
-		List<Resource> classes = new ArrayList<>();
-		for (ModuleReference reference : references) {
-			classes.addAll(scanner.scan(reference));
-		}
-		logger.debug(() -> "Found " + classes.size() + " classes: " + classes);
-		return Collections.unmodifiableList(classes);
-	}
-
-	/**
-	 * {@link ModuleReference} class scanner.
-	 *
-	 * @since 1.1
-	 */
-	static class ModuleReferenceClassScanner {
-
-		private final ClassFilter classFilter;
-		private final ClassLoader classLoader;
-
-		ModuleReferenceClassScanner(ClassFilter classFilter, ClassLoader classLoader) {
-			this.classFilter = classFilter;
-			this.classLoader = classLoader;
-		}
-
-		/**
-		 * Scan module reference for classes that potentially contain testable methods.
-		 */
-		List<Class<?>> scan(ModuleReference reference) {
-			try (ModuleReader reader = reference.open()) {
-				try (Stream<String> names = reader.list()) {
-					// @formatter:off
-					return names.filter(name -> name.endsWith(".class"))
-							.map(this::className)
-							.filter(name -> !name.equals("module-info"))
-							.filter(classFilter::match)
-							.map(this::loadClassUnchecked)
-							.filter(classFilter::match)
-							.collect(Collectors.toList());
-					// @formatter:on
-				}
-			}
-			catch (IOException e) {
-				throw new JUnitException("Failed to read contents of " + reference + ".", e);
-			}
-		}
-
-		/**
-		 * Convert resource name to binary class name.
-		 */
-		private String className(String resourceName) {
-			resourceName = resourceName.substring(0, resourceName.length() - 6); // 6 = ".class".length()
-			resourceName = resourceName.replace('/', '.');
-			return resourceName;
-		}
-
-		/**
-		 * Load class by its binary name.
-		 *
-		 * @see ClassLoader#loadClass(String)
-		 */
-		private Class<?> loadClassUnchecked(String binaryName) {
-			try {
-				return classLoader.loadClass(binaryName);
-			}
-			catch (ClassNotFoundException e) {
-				throw new JUnitException("Failed to load class with name '" + binaryName + "'.", e);
-			}
-		}
-
-	}
-
-	/**
-	 * {@link ModuleReference} resource class scanner.
-	 *
-	 * @since 1.11
-	 */
-	static class ModuleReferenceResourceScanner {
-
-		private final Predicate<Resource> resourceFilter;
-		private final ClassLoader classLoader;
-
-		ModuleReferenceResourceScanner(Predicate<Resource> resourceFilter, ClassLoader classLoader) {
-			this.resourceFilter = resourceFilter;
-			this.classLoader = classLoader;
-		}
-
-		/**
-		 * Scan module reference for resources that potentially contain testable resources.
-		 */
-		List<Resource> scan(ModuleReference reference) {
-			try (ModuleReader reader = reference.open()) {
-				try (Stream<String> names = reader.list()) {
-					// @formatter:off
-					return names.filter(name -> !name.endsWith(".class"))
-							.map(this::loadResourceUnchecked)
-							.filter(resourceFilter)
-							.collect(Collectors.toList());
-					// @formatter:on
-				}
-			}
-			catch (IOException e) {
-				throw new JUnitException("Failed to read contents of " + reference + ".", e);
-			}
-		}
-
-		private Resource loadResourceUnchecked(String binaryName) {
-			try {
-				URI uri = classLoader.getResource(binaryName).toURI();
-				return new DefaultResource(binaryName, uri);
-			}
-			catch (URISyntaxException e) {
-				throw new JUnitException("Failed to load resource with name '" + binaryName + "'.", e);
-			}
-		}
-
-	}
-
-}
diff --git a/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/PackageNameUtils.java b/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/PackageNameUtils.java
deleted file mode 100644
index 0cb6aec9e8d8..000000000000
--- a/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/PackageNameUtils.java
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * Copyright 2015-2025 the original author or authors.
- *
- * All rights reserved. This program and the accompanying materials are
- * made available under the terms of the Eclipse Public License v2.0 which
- * accompanies this distribution and is available at
- *
- * https://www.eclipse.org/legal/epl-v20.html
- */
-
-package org.junit.platform.commons.util;
-
-/**
- * Collection of utilities for working with package names.
- *
- * <h2>DISCLAIMER</h2>
- *
- * <p>These utilities are intended solely for usage within the JUnit framework
- * itself. <strong>Any usage by external parties is not supported.</strong>
- * Use at your own risk!
- *
- * @since 1.11.3
- */
-class PackageNameUtils {
-
-	static String getPackageName(Class<?> clazz) {
-		return clazz.getPackageName();
-	}
-
-}
diff --git a/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/ServiceLoaderUtils.java b/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/ServiceLoaderUtils.java
deleted file mode 100644
index 878c62a2c7e7..000000000000
--- a/junit-platform-commons/src/main/java9/org/junit/platform/commons/util/ServiceLoaderUtils.java
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright 2015-2025 the original author or authors.
- *
- * All rights reserved. This program and the accompanying materials are
- * made available under the terms of the Eclipse Public License v2.0 which
- * accompanies this distribution and is available at
- *
- * https://www.eclipse.org/legal/epl-v20.html
- */
-
-package org.junit.platform.commons.util;
-
-import java.util.ServiceLoader;
-import java.util.function.Predicate;
-import java.util.stream.Stream;
-
-import org.apiguardian.api.API;
-import org.apiguardian.api.API.Status;
-
-/**
- * Collection of utilities for working with {@link ServiceLoader}.
- *
- * <h2>DISCLAIMER</h2>
- *
- * <p>These utilities are intended solely for usage within the JUnit framework
- * itself. <strong>Any usage by external parties is not supported.</strong>
- * Use at your own risk!
- *
- * @since 5.11
- */
-@API(status = Status.INTERNAL, since = "5.11")
-public class ServiceLoaderUtils {
-
-	private ServiceLoaderUtils() {
-		/* no-op */
-	}
-
-	/**
-	 * Filters the supplied service loader using the supplied predicate.
-	 *
-	 * @param <T> the type of the service
-	 * @param serviceLoader the service loader to be filtered
-	 * @param providerPredicate the predicate to filter the loaded services
-	 * @return a stream of loaded services that match the predicate
-	 */
-	public static <T> Stream<T> filter(ServiceLoader<T> serviceLoader,
-			Predicate<? super Class<? extends T>> providerPredicate) {
-		// @formatter:off
-		return serviceLoader
-				.stream()
-				.filter(provider -> providerPredicate.test(provider.type()))
-				.map(ServiceLoader.Provider::get);
-		// @formatter:on
-	}
-
-}
diff --git a/junit-platform-console-standalone/junit-platform-console-standalone.gradle.kts b/junit-platform-console-standalone/junit-platform-console-standalone.gradle.kts
index a15f463a4d04..f1859d463a37 100644
--- a/junit-platform-console-standalone/junit-platform-console-standalone.gradle.kts
+++ b/junit-platform-console-standalone/junit-platform-console-standalone.gradle.kts
@@ -85,12 +85,4 @@ tasks {
 			))
 		}
 	}
-
-	// This jar contains some Java 9 code
-	// (org.junit.platform.console.ConsoleLauncherToolProvider which implements
-	// java.util.spi.ToolProvider which is @since 9).
-	// So in order to resolve this, it can only run on Java 9
-	osgiProperties {
-		property("-runee", "JavaSE-9")
-	}
 }
diff --git a/junit-platform-console/junit-platform-console.gradle.kts b/junit-platform-console/junit-platform-console.gradle.kts
index cd256959b629..586b30004004 100644
--- a/junit-platform-console/junit-platform-console.gradle.kts
+++ b/junit-platform-console/junit-platform-console.gradle.kts
@@ -3,7 +3,6 @@ import junitbuild.java.UpdateJarAction
 plugins {
 	id("junitbuild.java-library-conventions")
 	id("junitbuild.shadow-conventions")
-	id("junitbuild.java-multi-release-sources")
 }
 
 description = "JUnit Platform Console"
@@ -33,22 +32,17 @@ tasks {
 		))
 	}
 	shadowJar {
-		val release17ClassesDir = sourceSets.mainRelease17.get().output.classesDirs.singleFile
-		inputs.dir(release17ClassesDir).withPathSensitivity(PathSensitivity.RELATIVE)
 		exclude("META-INF/versions/9/module-info.class")
 		relocate("picocli", "org.junit.platform.console.shadow.picocli")
 		from(projectDir) {
 			include("LICENSE-picocli.md")
 			into("META-INF")
 		}
-		from(sourceSets.mainRelease9.get().output.classesDirs)
 		doLast(objects.newInstance(UpdateJarAction::class).apply {
 			javaLauncher = project.javaToolchains.launcherFor(java.toolchain)
 			args.addAll(
 				"--file", archiveFile.get().asFile.absolutePath,
 				"--main-class", "org.junit.platform.console.ConsoleLauncher",
-				"--release", "17",
-				"-C", release17ClassesDir.absolutePath, "."
 			)
 		})
 	}
@@ -60,19 +54,4 @@ tasks {
 			attributes("Main-Class" to "org.junit.platform.console.ConsoleLauncher")
 		}
 	}
-
-	// This jar contains some Java 9 code
-	// (org.junit.platform.console.ConsoleLauncherToolProvider which implements
-	// java.util.spi.ToolProvider which is @since 9).
-	// So in order to resolve this, it can only run on Java 9
-	osgiProperties {
-		property("-runee", "JavaSE-9")
-	}
-}
-
-eclipse {
-	classpath {
-		sourceSets -= project.sourceSets.mainRelease9.get()
-		sourceSets -= project.sourceSets.mainRelease17.get()
-	}
 }
diff --git a/junit-platform-console/src/main/java9/org/junit/platform/console/ConsoleLauncherToolProvider.java b/junit-platform-console/src/main/java/org/junit/platform/console/ConsoleLauncherToolProvider.java
similarity index 100%
rename from junit-platform-console/src/main/java9/org/junit/platform/console/ConsoleLauncherToolProvider.java
rename to junit-platform-console/src/main/java/org/junit/platform/console/ConsoleLauncherToolProvider.java
diff --git a/junit-platform-console/src/main/java/org/junit/platform/console/options/ConsoleUtils.java b/junit-platform-console/src/main/java/org/junit/platform/console/options/ConsoleUtils.java
index ed82e426dca0..145ebed63fd4 100644
--- a/junit-platform-console/src/main/java/org/junit/platform/console/options/ConsoleUtils.java
+++ b/junit-platform-console/src/main/java/org/junit/platform/console/options/ConsoleUtils.java
@@ -12,6 +12,7 @@
 
 import static org.apiguardian.api.API.Status.INTERNAL;
 
+import java.io.Console;
 import java.nio.charset.Charset;
 
 import org.apiguardian.api.API;
@@ -35,6 +36,7 @@ public class ConsoleUtils {
 	 * {@return the charset of the console}
 	 */
 	public static Charset charset() {
-		return Charset.defaultCharset();
+		Console console = System.console();
+		return console != null ? console.charset() : Charset.defaultCharset();
 	}
 }
diff --git a/junit-platform-console/src/main/java17/org/junit/platform/console/options/ConsoleUtils.java b/junit-platform-console/src/main/java17/org/junit/platform/console/options/ConsoleUtils.java
deleted file mode 100644
index 145ebed63fd4..000000000000
--- a/junit-platform-console/src/main/java17/org/junit/platform/console/options/ConsoleUtils.java
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright 2015-2025 the original author or authors.
- *
- * All rights reserved. This program and the accompanying materials are
- * made available under the terms of the Eclipse Public License v2.0 which
- * accompanies this distribution and is available at
- *
- * https://www.eclipse.org/legal/epl-v20.html
- */
-
-package org.junit.platform.console.options;
-
-import static org.apiguardian.api.API.Status.INTERNAL;
-
-import java.io.Console;
-import java.nio.charset.Charset;
-
-import org.apiguardian.api.API;
-
-/**
- * Collection of utilities for working with {@code java.io.Console}
- * and friends.
- *
- * <h2>DISCLAIMER</h2>
- *
- * <p>These utilities are intended solely for usage within the JUnit framework
- * itself. <strong>Any usage by external parties is not supported.</strong>
- * Use at your own risk!
- *
- * @since 1.9
- */
-@API(status = INTERNAL, since = "1.9")
-public class ConsoleUtils {
-
-	/**
-	 * {@return the charset of the console}
-	 */
-	public static Charset charset() {
-		Console console = System.console();
-		return console != null ? console.charset() : Charset.defaultCharset();
-	}
-}
diff --git a/junit-platform-jfr/junit-platform-jfr.gradle.kts b/junit-platform-jfr/junit-platform-jfr.gradle.kts
index 0f03e2b99f86..8d82379addad 100644
--- a/junit-platform-jfr/junit-platform-jfr.gradle.kts
+++ b/junit-platform-jfr/junit-platform-jfr.gradle.kts
@@ -20,17 +20,7 @@ dependencies {
 	osgiVerification(projects.junitPlatformLauncher)
 }
 
-javaLibrary {
-	// --release 8 does not support jdk.jfr even though it was backported
-	configureRelease = false
-}
-
 tasks {
-	compileJava {
-		javaCompiler = project.javaToolchains.compilerFor {
-			languageVersion = JavaLanguageVersion.of(8)
-		}
-	}
 	compileModule {
 		options.release = 11
 	}
diff --git a/platform-tooling-support-tests/platform-tooling-support-tests.gradle.kts b/platform-tooling-support-tests/platform-tooling-support-tests.gradle.kts
index 9e5b70ba9ef2..780a81075e28 100644
--- a/platform-tooling-support-tests/platform-tooling-support-tests.gradle.kts
+++ b/platform-tooling-support-tests/platform-tooling-support-tests.gradle.kts
@@ -173,12 +173,12 @@ tasks.test {
 
 	develocity {
 		testDistribution {
-			requirements.add("jdk=8")
+			requirements.add("jdk=17")
 			this as TestDistributionConfigurationInternal
 			preferredMaxDuration = Duration.ofMillis(500)
 		}
 	}
-	jvmArgumentProviders += JavaHomeDir(project, 8, develocity.testDistribution.enabled)
+	jvmArgumentProviders += JavaHomeDir(project, 17, develocity.testDistribution.enabled)
 
 	val gradleJavaVersion = JavaVersion.current().majorVersion.toInt()
 	jvmArgumentProviders += JavaHomeDir(project, gradleJavaVersion, develocity.testDistribution.enabled)
diff --git a/platform-tooling-support-tests/projects/gradle-kotlin-extensions/build.gradle.kts b/platform-tooling-support-tests/projects/gradle-kotlin-extensions/build.gradle.kts
index 5f343d010524..38fa8f92fdce 100644
--- a/platform-tooling-support-tests/projects/gradle-kotlin-extensions/build.gradle.kts
+++ b/platform-tooling-support-tests/projects/gradle-kotlin-extensions/build.gradle.kts
@@ -13,20 +13,20 @@ val jupiterVersion: String by project
 val platformVersion: String by project
 
 dependencies {
-	testImplementation(kotlin("stdlib-jdk8"))
+	testImplementation(kotlin("stdlib"))
 	testImplementation("org.junit.jupiter:junit-jupiter:$jupiterVersion")
 	testRuntimeOnly("org.junit.platform:junit-platform-launcher:$platformVersion")
 }
 
 java {
 	toolchain {
-		languageVersion = JavaLanguageVersion.of(8)
+		languageVersion = JavaLanguageVersion.of(17)
 	}
 }
 
 tasks.withType<KotlinCompile>().configureEach {
 	kotlinOptions {
-		jvmTarget = "1.8"
+		jvmTarget = "17"
 		apiVersion = "1.6"
 		languageVersion = "1.6"
 	}
diff --git a/platform-tooling-support-tests/projects/gradle-kotlin-extensions/gradle.properties b/platform-tooling-support-tests/projects/gradle-kotlin-extensions/gradle.properties
index 79b428ebc70c..bed2250e4577 100644
--- a/platform-tooling-support-tests/projects/gradle-kotlin-extensions/gradle.properties
+++ b/platform-tooling-support-tests/projects/gradle-kotlin-extensions/gradle.properties
@@ -1 +1 @@
-org.gradle.java.installations.fromEnv=JDK8
+org.gradle.java.installations.fromEnv=JDK17
diff --git a/platform-tooling-support-tests/projects/gradle-missing-engine/build.gradle.kts b/platform-tooling-support-tests/projects/gradle-missing-engine/build.gradle.kts
index 50b4e7b2924b..0e7c2e9ac3b3 100644
--- a/platform-tooling-support-tests/projects/gradle-missing-engine/build.gradle.kts
+++ b/platform-tooling-support-tests/projects/gradle-missing-engine/build.gradle.kts
@@ -18,7 +18,7 @@ dependencies {
 
 java {
 	toolchain {
-		languageVersion = JavaLanguageVersion.of(8)
+		languageVersion = JavaLanguageVersion.of(17)
 	}
 }
 
diff --git a/platform-tooling-support-tests/projects/gradle-missing-engine/gradle.properties b/platform-tooling-support-tests/projects/gradle-missing-engine/gradle.properties
index 79b428ebc70c..bed2250e4577 100644
--- a/platform-tooling-support-tests/projects/gradle-missing-engine/gradle.properties
+++ b/platform-tooling-support-tests/projects/gradle-missing-engine/gradle.properties
@@ -1 +1 @@
-org.gradle.java.installations.fromEnv=JDK8
+org.gradle.java.installations.fromEnv=JDK17
diff --git a/platform-tooling-support-tests/projects/gradle-starter/build.gradle.kts b/platform-tooling-support-tests/projects/gradle-starter/build.gradle.kts
index 751889da23d0..01738a2c1956 100644
--- a/platform-tooling-support-tests/projects/gradle-starter/build.gradle.kts
+++ b/platform-tooling-support-tests/projects/gradle-starter/build.gradle.kts
@@ -17,7 +17,7 @@ dependencies {
 
 java {
 	toolchain {
-		languageVersion = JavaLanguageVersion.of(8)
+		languageVersion = JavaLanguageVersion.of(17)
 	}
 }
 
diff --git a/platform-tooling-support-tests/projects/gradle-starter/gradle.properties b/platform-tooling-support-tests/projects/gradle-starter/gradle.properties
index 79b428ebc70c..bed2250e4577 100644
--- a/platform-tooling-support-tests/projects/gradle-starter/gradle.properties
+++ b/platform-tooling-support-tests/projects/gradle-starter/gradle.properties
@@ -1 +1 @@
-org.gradle.java.installations.fromEnv=JDK8
+org.gradle.java.installations.fromEnv=JDK17
diff --git a/platform-tooling-support-tests/projects/java-versions/pom.xml b/platform-tooling-support-tests/projects/java-versions/pom.xml
deleted file mode 100644
index d9d22bbec6b6..000000000000
--- a/platform-tooling-support-tests/projects/java-versions/pom.xml
+++ /dev/null
@@ -1,63 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-
-    <groupId>platform.tooling.support.tests</groupId>
-    <artifactId>java-versions</artifactId>
-    <version>1.0-SNAPSHOT</version>
-
-    <properties>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    </properties>
-
-    <dependencies>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <version>${junit.jupiter.version}</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.junit.platform</groupId>
-            <artifactId>junit-platform-commons</artifactId>
-            <version>${junit.platform.version}</version>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <artifactId>maven-compiler-plugin</artifactId>
-                    <version>3.13.0</version>
-                    <configuration>
-                        <source>1.8</source>
-                        <target>1.8</target>
-                    </configuration>
-                </plugin>
-                <plugin>
-                    <artifactId>maven-surefire-plugin</artifactId>
-                    <version>3.5.2</version>
-                </plugin>
-            </plugins>
-        </pluginManagement>
-    </build>
-
-    <repositories>
-        <repository>
-            <id>local-temp</id>
-            <url>file://${maven.repo}</url>
-            <snapshots>
-                <enabled>true</enabled>
-                <checksumPolicy>ignore</checksumPolicy>
-            </snapshots>
-            <releases>
-                <enabled>true</enabled>
-                <checksumPolicy>ignore</checksumPolicy>
-            </releases>
-        </repository>
-    </repositories>
-
-</project>
diff --git a/platform-tooling-support-tests/projects/java-versions/src/test/java/JUnitPlatformCommonsTests.java b/platform-tooling-support-tests/projects/java-versions/src/test/java/JUnitPlatformCommonsTests.java
deleted file mode 100644
index 7e7a888bdd6b..000000000000
--- a/platform-tooling-support-tests/projects/java-versions/src/test/java/JUnitPlatformCommonsTests.java
+++ /dev/null
@@ -1,37 +0,0 @@
-
-/*
- * Copyright 2015-2025 the original author or authors.
- *
- * All rights reserved. This program and the accompanying materials are
- * made available under the terms of the Eclipse Public License v2.0 which
- * accompanies this distribution and is available at
- *
- * https://www.eclipse.org/legal/epl-v20.html
- */
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.DisabledOnJre;
-import org.junit.jupiter.api.condition.EnabledOnJre;
-import org.junit.jupiter.api.condition.JRE;
-import org.junit.platform.commons.util.ModuleUtils;
-
-class JUnitPlatformCommonsTests {
-
-	@Test
-	@EnabledOnJre(JRE.JAVA_8)
-	void onJava8() {
-		assertFalse(ModuleUtils.isJavaPlatformModuleSystemAvailable());
-		assertFalse(ModuleUtils.getModuleName(Object.class).isPresent());
-	}
-
-	@Test
-	@DisabledOnJre(JRE.JAVA_8)
-	void onJava9OrHigher() {
-		assertTrue(ModuleUtils.isJavaPlatformModuleSystemAvailable());
-		assertEquals("java.base", ModuleUtils.getModuleName(Object.class).orElseThrow(Error::new));
-	}
-
-}
diff --git a/platform-tooling-support-tests/projects/maven-starter/pom.xml b/platform-tooling-support-tests/projects/maven-starter/pom.xml
index c03e69a3277c..6ec91455e3ca 100644
--- a/platform-tooling-support-tests/projects/maven-starter/pom.xml
+++ b/platform-tooling-support-tests/projects/maven-starter/pom.xml
@@ -9,8 +9,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>${maven.compiler.source}</maven.compiler.target>
+        <maven.compiler.release>17</maven.compiler.release>
         <junit.platform.commons.version>${junit.platform.version}</junit.platform.commons.version>
     </properties>
 
diff --git a/platform-tooling-support-tests/projects/maven-surefire-compatibility/pom.xml b/platform-tooling-support-tests/projects/maven-surefire-compatibility/pom.xml
index 3ac0876b2d8b..3836c489d6d8 100644
--- a/platform-tooling-support-tests/projects/maven-surefire-compatibility/pom.xml
+++ b/platform-tooling-support-tests/projects/maven-surefire-compatibility/pom.xml
@@ -9,8 +9,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>${maven.compiler.source}</maven.compiler.target>
+        <maven.compiler.release>17</maven.compiler.release>
     </properties>
 
     <dependencies>
diff --git a/platform-tooling-support-tests/projects/reflection-tests/build.gradle.kts b/platform-tooling-support-tests/projects/reflection-tests/build.gradle.kts
index 0dea5aab80a1..88cc4dff4bb4 100644
--- a/platform-tooling-support-tests/projects/reflection-tests/build.gradle.kts
+++ b/platform-tooling-support-tests/projects/reflection-tests/build.gradle.kts
@@ -18,7 +18,7 @@ dependencies {
 
 java {
 	toolchain {
-		languageVersion = JavaLanguageVersion.of(8)
+		languageVersion = JavaLanguageVersion.of(17)
 	}
 }
 
diff --git a/platform-tooling-support-tests/projects/reflection-tests/gradle.properties b/platform-tooling-support-tests/projects/reflection-tests/gradle.properties
index 79b428ebc70c..bed2250e4577 100644
--- a/platform-tooling-support-tests/projects/reflection-tests/gradle.properties
+++ b/platform-tooling-support-tests/projects/reflection-tests/gradle.properties
@@ -1 +1 @@
-org.gradle.java.installations.fromEnv=JDK8
+org.gradle.java.installations.fromEnv=JDK17
diff --git a/platform-tooling-support-tests/projects/vintage/build.gradle.kts b/platform-tooling-support-tests/projects/vintage/build.gradle.kts
index 37bab7448d5b..efa61d4ac9c1 100644
--- a/platform-tooling-support-tests/projects/vintage/build.gradle.kts
+++ b/platform-tooling-support-tests/projects/vintage/build.gradle.kts
@@ -26,7 +26,7 @@ dependencies {
 
 java {
 	toolchain {
-		languageVersion = JavaLanguageVersion.of(8)
+		languageVersion = JavaLanguageVersion.of(17)
 	}
 }
 
diff --git a/platform-tooling-support-tests/projects/vintage/gradle.properties b/platform-tooling-support-tests/projects/vintage/gradle.properties
index 79b428ebc70c..bed2250e4577 100644
--- a/platform-tooling-support-tests/projects/vintage/gradle.properties
+++ b/platform-tooling-support-tests/projects/vintage/gradle.properties
@@ -1 +1 @@
-org.gradle.java.installations.fromEnv=JDK8
+org.gradle.java.installations.fromEnv=JDK17
diff --git a/platform-tooling-support-tests/projects/vintage/pom.xml b/platform-tooling-support-tests/projects/vintage/pom.xml
index 164570994740..2f652775366b 100644
--- a/platform-tooling-support-tests/projects/vintage/pom.xml
+++ b/platform-tooling-support-tests/projects/vintage/pom.xml
@@ -9,8 +9,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>${maven.compiler.source}</maven.compiler.target>
+        <maven.compiler.release>17</maven.compiler.release>
     </properties>
 
     <dependencies>
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/HelperTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/HelperTests.java
index 6aaa2b1c29be..2fc8fbfdfbfc 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/HelperTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/HelperTests.java
@@ -65,7 +65,7 @@ void nonExistingJdkVersionYieldsAnEmptyOptional() {
 	}
 
 	@ParameterizedTest
-	@ValueSource(ints = 8)
+	@ValueSource(ints = 17)
 	void checkJavaHome(int version) {
 		var home = Helper.getJavaHome(String.valueOf(version));
 		assumeTrue(home.isPresent(), "No 'jdk' element found in Maven toolchain for: " + version);
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleKotlinExtensionsTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleKotlinExtensionsTests.java
index 6c05aef99240..54d7db513984 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleKotlinExtensionsTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleKotlinExtensionsTests.java
@@ -36,7 +36,7 @@ void gradle_wrapper(@TempDir Path workspace, @FilePrefix("gradle") OutputFiles o
 				.workingDir(copyToWorkspace(Projects.GRADLE_KOTLIN_EXTENSIONS, workspace)) //
 				.addArguments("-Dmaven.repo=" + MavenRepo.dir()) //
 				.addArguments("build", "--no-daemon", "--stacktrace", "--no-build-cache", "--warning-mode=fail") //
-				.putEnvironment("JDK8", Helper.getJavaHome("8").orElseThrow(TestAbortedException::new).toString()) //
+				.putEnvironment("JDK17", Helper.getJavaHome("17").orElseThrow(TestAbortedException::new).toString()) //
 				.redirectOutput(outputFiles) //
 				.startAndWait();
 
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleMissingEngineTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleMissingEngineTests.java
index fdc04d46445e..977c9c702d11 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleMissingEngineTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleMissingEngineTests.java
@@ -37,7 +37,7 @@ void gradle_wrapper(@TempDir Path workspace, @FilePrefix("gradle") OutputFiles o
 				.workingDir(copyToWorkspace(Projects.GRADLE_MISSING_ENGINE, workspace)) //
 				.addArguments("-Dmaven.repo=" + MavenRepo.dir()) //
 				.addArguments("build", "--no-daemon", "--stacktrace", "--no-build-cache", "--warning-mode=fail") //
-				.putEnvironment("JDK8", Helper.getJavaHome("8").orElseThrow(TestAbortedException::new).toString()) //
+				.putEnvironment("JDK17", Helper.getJavaHome("17").orElseThrow(TestAbortedException::new).toString()) //
 				.redirectOutput(outputFiles).startAndWait();
 
 		assertEquals(1, result.exitCode());
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleModuleFileTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleModuleFileTests.java
index c79c2b4e54f4..ca5b03192965 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleModuleFileTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleModuleFileTests.java
@@ -46,7 +46,7 @@ void jupiterAggregatorGradleModuleMetadataVariants() throws Exception {
 			"      \"attributes\": {", //
 			"        \"org.gradle.category\": \"library\",", //
 			"        \"org.gradle.dependency.bundling\": \"external\",", //
-			"        \"org.gradle.jvm.version\": 8,", //
+			"        \"org.gradle.jvm.version\": 17,", //
 			"        \"org.gradle.libraryelements\": \"jar\",", //
 			"        \"org.gradle.usage\": \"java-api\"", //
 			"      },", //
@@ -88,7 +88,7 @@ void jupiterAggregatorGradleModuleMetadataVariants() throws Exception {
 			"      \"attributes\": {", //
 			"        \"org.gradle.category\": \"library\",", //
 			"        \"org.gradle.dependency.bundling\": \"external\",", //
-			"        \"org.gradle.jvm.version\": 8,", //
+			"        \"org.gradle.jvm.version\": 17,", //
 			"        \"org.gradle.libraryelements\": \"jar\",", //
 			"        \"org.gradle.usage\": \"java-runtime\"", //
 			"      },", //
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleStarterTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleStarterTests.java
index 95d0a14a23f2..ef1c4f905b0f 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleStarterTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/GradleStarterTests.java
@@ -38,13 +38,13 @@ void gradle_wrapper(@TempDir Path workspace, @FilePrefix("gradle") OutputFiles o
 				.workingDir(copyToWorkspace(Projects.GRADLE_STARTER, workspace)) //
 				.addArguments("-Dmaven.repo=" + MavenRepo.dir()) //
 				.addArguments("build", "--no-daemon", "--stacktrace", "--no-build-cache", "--warning-mode=fail") //
-				.putEnvironment("JDK8", Helper.getJavaHome("8").orElseThrow(TestAbortedException::new).toString()) //
+				.putEnvironment("JDK17", Helper.getJavaHome("17").orElseThrow(TestAbortedException::new).toString()) //
 				.redirectOutput(outputFiles) //
 				.startAndWait();
 
 		assertEquals(0, result.exitCode());
 		assertTrue(result.stdOut().lines().anyMatch(line -> line.contains("BUILD SUCCESSFUL")));
-		assertThat(result.stdOut()).contains("Using Java version: 1.8");
+		assertThat(result.stdOut()).contains("Using Java version: 17");
 
 		var testResultsDir = workspace.resolve("build/test-results/test");
 		verifyContainsExpectedStartedOpenTestReport(testResultsDir);
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/JavaVersionsTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/JavaVersionsTests.java
deleted file mode 100644
index 4a7cce72c99e..000000000000
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/JavaVersionsTests.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright 2015-2025 the original author or authors.
- *
- * All rights reserved. This program and the accompanying materials are
- * made available under the terms of the Eclipse Public License v2.0 which
- * accompanies this distribution and is available at
- *
- * https://www.eclipse.org/legal/epl-v20.html
- */
-
-package platform.tooling.support.tests;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assumptions.assumeTrue;
-import static platform.tooling.support.ProcessStarters.currentJdkHome;
-import static platform.tooling.support.tests.Projects.copyToWorkspace;
-
-import java.nio.file.Path;
-import java.util.List;
-import java.util.Map;
-
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.JRE;
-import org.junit.jupiter.api.io.TempDir;
-import org.junit.platform.tests.process.OutputFiles;
-
-import platform.tooling.support.Helper;
-import platform.tooling.support.MavenRepo;
-import platform.tooling.support.ProcessStarters;
-
-/**
- * @since 1.4
- */
-class JavaVersionsTests {
-
-	@GlobalResource
-	LocalMavenRepo localMavenRepo;
-
-	@TempDir
-	Path workspace;
-
-	@Test
-	void java_8(@FilePrefix("maven") OutputFiles outputFiles) throws Exception {
-		var java8Home = Helper.getJavaHome("8");
-		assumeTrue(java8Home.isPresent(), "Java 8 installation directory not found!");
-		var actualLines = execute(java8Home.get(), outputFiles, Map.of());
-
-		assertTrue(actualLines.contains("[WARNING] Tests run: 2, Failures: 0, Errors: 0, Skipped: 1"));
-	}
-
-	@Test
-	void java_default(@FilePrefix("maven") OutputFiles outputFiles) throws Exception {
-		var actualLines = execute(currentJdkHome(), outputFiles, MavenEnvVars.forJre(JRE.currentVersion()));
-
-		assertTrue(actualLines.contains("[WARNING] Tests run: 2, Failures: 0, Errors: 0, Skipped: 1"));
-	}
-
-	List<String> execute(Path javaHome, OutputFiles outputFiles, Map<String, String> environmentVars) throws Exception {
-		var result = ProcessStarters.maven(javaHome) //
-				.workingDir(copyToWorkspace(Projects.JAVA_VERSIONS, workspace)) //
-				.putEnvironment(environmentVars) //
-				.addArguments(localMavenRepo.toCliArgument(), "-Dmaven.repo=" + MavenRepo.dir()) //
-				.addArguments("--update-snapshots", "--batch-mode", "verify") //
-				.startAndWait();
-
-		assertEquals(0, result.exitCode());
-		assertEquals("", result.stdErr());
-		return result.stdOutLines();
-	}
-
-}
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ManifestTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ManifestTests.java
index d215ca8e99c0..335053898a13 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ManifestTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ManifestTests.java
@@ -56,10 +56,8 @@ void manifestEntriesAdhereToConventions(String module) throws Exception {
 			assertValue(attributes, "Bundle-SymbolicName", module);
 			assertValue(attributes, "Bundle-Version",
 				MavenVersion.parseMavenString(version).getOSGiVersion().toString());
-			switch (module) {
-				case "junit-platform-commons" -> assertValue(attributes, "Multi-Release", "true");
-				case "junit-platform-console" -> assertValue(attributes, "Main-Class",
-					"org.junit.platform.console.ConsoleLauncher");
+			if (module.equals("junit-platform-console")) {
+				assertValue(attributes, "Main-Class", "org.junit.platform.console.ConsoleLauncher");
 			}
 			var domain = Domain.domain(manifest);
 			domain.getExportPackage().forEach((pkg, attrs) -> {
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/MavenStarterTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/MavenStarterTests.java
index 9faf699942ea..751ca5c41ece 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/MavenStarterTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/MavenStarterTests.java
@@ -41,7 +41,7 @@ class MavenStarterTests {
 	@Test
 	void verifyMavenStarterProject(@TempDir Path workspace, @FilePrefix("maven") OutputFiles outputFiles)
 			throws Exception {
-		var result = ProcessStarters.maven(Helper.getJavaHome("8").orElseThrow(TestAbortedException::new)) //
+		var result = ProcessStarters.maven(Helper.getJavaHome("17").orElseThrow(TestAbortedException::new)) //
 				.workingDir(copyToWorkspace(Projects.MAVEN_STARTER, workspace)) //
 				.addArguments(localMavenRepo.toCliArgument(), "-Dmaven.repo=" + MavenRepo.dir()) //
 				.addArguments("-Dsnapshot.repo.url=" + mavenRepoProxy.getBaseUri()) //
@@ -53,7 +53,7 @@ void verifyMavenStarterProject(@TempDir Path workspace, @FilePrefix("maven") Out
 		assertEquals("", result.stdErr());
 		assertTrue(result.stdOutLines().contains("[INFO] BUILD SUCCESS"));
 		assertTrue(result.stdOutLines().contains("[INFO] Tests run: 5, Failures: 0, Errors: 0, Skipped: 0"));
-		assertThat(result.stdOut()).contains("Using Java version: 1.8");
+		assertThat(result.stdOut()).contains("Using Java version: 17");
 
 		var testResultsDir = workspace.resolve("target/surefire-reports");
 		verifyContainsExpectedStartedOpenTestReport(testResultsDir);
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/MavenSurefireCompatibilityTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/MavenSurefireCompatibilityTests.java
index a59d90ecbf53..1f20e608fdc3 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/MavenSurefireCompatibilityTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/MavenSurefireCompatibilityTests.java
@@ -44,7 +44,7 @@ class MavenSurefireCompatibilityTests {
 	void testMavenSurefireCompatibilityProject(String surefireVersion, String extraArg, @TempDir Path workspace,
 			@FilePrefix("maven") OutputFiles outputFiles) throws Exception {
 		var extraArgs = extraArg == null ? new String[0] : new String[] { extraArg };
-		var result = ProcessStarters.maven(Helper.getJavaHome("8").orElseThrow(TestAbortedException::new)) //
+		var result = ProcessStarters.maven(Helper.getJavaHome("17").orElseThrow(TestAbortedException::new)) //
 				.workingDir(copyToWorkspace(Projects.MAVEN_SUREFIRE_COMPATIBILITY, workspace)) //
 				.addArguments(localMavenRepo.toCliArgument(), "-Dmaven.repo=" + MavenRepo.dir()) //
 				.addArguments("-Dsurefire.version=" + surefireVersion) //
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ReflectionCompatibilityTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ReflectionCompatibilityTests.java
index bc9135a1cc54..8c3b6231fc1f 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ReflectionCompatibilityTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ReflectionCompatibilityTests.java
@@ -37,12 +37,12 @@ void gradle_wrapper(@TempDir Path workspace, @FilePrefix("gradle") OutputFiles o
 				.workingDir(copyToWorkspace(Projects.REFLECTION_TESTS, workspace)) //
 				.addArguments("-Dmaven.repo=" + MavenRepo.dir()) //
 				.addArguments("build", "--no-daemon", "--stacktrace", "--no-build-cache", "--warning-mode=fail") //
-				.putEnvironment("JDK8", Helper.getJavaHome("8").orElseThrow(TestAbortedException::new).toString()) //
+				.putEnvironment("JDK17", Helper.getJavaHome("17").orElseThrow(TestAbortedException::new).toString()) //
 				.redirectOutput(outputFiles) //
 				.startAndWait();
 
 		assertEquals(0, result.exitCode());
 		assertTrue(result.stdOut().lines().anyMatch(line -> line.contains("BUILD SUCCESSFUL")));
-		assertThat(result.stdOut()).contains("Using Java version: 1.8");
+		assertThat(result.stdOut()).contains("Using Java version: 17");
 	}
 }
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/StandaloneTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/StandaloneTests.java
index 6cbb5bc931e1..65ae4f67d3e8 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/StandaloneTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/StandaloneTests.java
@@ -160,7 +160,7 @@ void compile(@FilePrefix("javac") OutputFiles javacOutputFiles, @FilePrefix("jar
 		var result = ProcessStarters.javaCommand("javac") //
 				.workingDir(workspace) //
 				.addArguments("-Xlint:-options") //
-				.addArguments("--release", "8") //
+				.addArguments("--release", "17") //
 				.addArguments("-proc:none") //
 				.addArguments("-d", workspace.resolve("bin").toString()) //
 				.addArguments("--class-path", MavenRepo.jar("junit-platform-console-standalone").toString()) //
@@ -453,9 +453,9 @@ void execute(@FilePrefix("console-launcher") OutputFiles outputFiles) throws Exc
 	@Test
 	@Order(4)
 	@Execution(SAME_THREAD)
-	void executeOnJava8(@FilePrefix("console-launcher") OutputFiles outputFiles) throws Exception {
-		var java8Home = Helper.getJavaHome("8").orElseThrow(TestAbortedException::new);
-		var result = ProcessStarters.java(java8Home) //
+	void executeOnJava17(@FilePrefix("console-launcher") OutputFiles outputFiles) throws Exception {
+		var javaHome = Helper.getJavaHome("17").orElseThrow(TestAbortedException::new);
+		var result = ProcessStarters.java(javaHome) //
 				.workingDir(workspace) //
 				.addArguments("-showversion") //
 				.addArguments("-enableassertions") //
@@ -473,7 +473,7 @@ void executeOnJava8(@FilePrefix("console-launcher") OutputFiles outputFiles) thr
 		assertEquals(1, result.exitCode());
 
 		var expectedOutLines = Files.readAllLines(workspace.resolve("expected-out.txt"));
-		var expectedErrLines = getExpectedErrLinesOnJava8(workspace);
+		var expectedErrLines = getExpectedErrLinesOnJava17(workspace);
 		assertLinesMatch(expectedOutLines, result.stdOutLines());
 		assertLinesMatch(expectedErrLines, result.stdErrLines());
 
@@ -489,9 +489,9 @@ void executeOnJava8(@FilePrefix("console-launcher") OutputFiles outputFiles) thr
 	@Order(5)
 	@Execution(SAME_THREAD)
 	// https://github.com/junit-team/junit5/issues/2600
-	void executeOnJava8SelectPackage(@FilePrefix("console-launcher") OutputFiles outputFiles) throws Exception {
-		var java8Home = Helper.getJavaHome("8").orElseThrow(TestAbortedException::new);
-		var result = ProcessStarters.java(java8Home) //
+	void executeOnJava17SelectPackage(@FilePrefix("console-launcher") OutputFiles outputFiles) throws Exception {
+		var javaHome = Helper.getJavaHome("17").orElseThrow(TestAbortedException::new);
+		var result = ProcessStarters.java(javaHome) //
 				.workingDir(workspace).addArguments("-showversion") //
 				.addArguments("-enableassertions") //
 				.addArguments("-Djava.util.logging.config.file=logging.properties") //
@@ -508,7 +508,7 @@ void executeOnJava8SelectPackage(@FilePrefix("console-launcher") OutputFiles out
 		assertEquals(1, result.exitCode());
 
 		var expectedOutLines = Files.readAllLines(workspace.resolve("expected-out.txt"));
-		var expectedErrLines = getExpectedErrLinesOnJava8(workspace);
+		var expectedErrLines = getExpectedErrLinesOnJava17(workspace);
 		assertLinesMatch(expectedOutLines, result.stdOutLines());
 		assertLinesMatch(expectedErrLines, result.stdErrLines());
 
@@ -520,7 +520,7 @@ void executeOnJava8SelectPackage(@FilePrefix("console-launcher") OutputFiles out
 				+ " (group ID: org.junit.vintage, artifact ID: junit-vintage-engine, version: " + vintageVersion));
 	}
 
-	private static List<String> getExpectedErrLinesOnJava8(Path workspace) throws IOException {
+	private static List<String> getExpectedErrLinesOnJava17(Path workspace) throws IOException {
 		var expectedErrLines = new ArrayList<String>();
 		expectedErrLines.add(">> JAVA VERSION >>");
 		expectedErrLines.addAll(Files.readAllLines(workspace.resolve("expected-err.txt")));
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/UnalignedClasspathTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/UnalignedClasspathTests.java
index a6467c511564..885cf901311c 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/UnalignedClasspathTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/UnalignedClasspathTests.java
@@ -68,7 +68,7 @@ void verifyErrorMessageForUnalignedClasspath(JRE jre, Path javaHome, @TempDir Pa
 
 	static Stream<Arguments> javaVersions() {
 		return Stream.concat( //
-			Helper.getJavaHome("8").map(path -> Arguments.of(JRE.JAVA_8, path)).stream(), //
+			Helper.getJavaHome("17").map(path -> Arguments.of(JRE.JAVA_17, path)).stream(), //
 			Stream.of(Arguments.of(JRE.currentVersion(), currentJdkHome())) //
 		);
 	}
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/VintageGradleIntegrationTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/VintageGradleIntegrationTests.java
index 39a02d21168e..36e059d0a51f 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/VintageGradleIntegrationTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/VintageGradleIntegrationTests.java
@@ -59,7 +59,7 @@ void supportedVersions(String version, @FilePrefix("gradle") OutputFiles outputF
 	private ProcessResult run(OutputFiles outputFiles, String version) throws Exception {
 		return ProcessStarters.gradlew() //
 				.workingDir(copyToWorkspace(Projects.VINTAGE, workspace)) //
-				.putEnvironment("JDK8", Helper.getJavaHome("8").orElseThrow(TestAbortedException::new).toString()) //
+				.putEnvironment("JDK17", Helper.getJavaHome("17").orElseThrow(TestAbortedException::new).toString()) //
 				.addArguments("build", "--no-daemon", "--stacktrace", "--no-build-cache", "--warning-mode=fail") //
 				.addArguments("-Dmaven.repo=" + MavenRepo.dir()) //
 				.addArguments("-Djunit4Version=" + version) //
diff --git a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/VintageMavenIntegrationTests.java b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/VintageMavenIntegrationTests.java
index 7f735753f009..f7c8f5a8ed1c 100644
--- a/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/VintageMavenIntegrationTests.java
+++ b/platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/VintageMavenIntegrationTests.java
@@ -62,7 +62,7 @@ void supportedVersions(String version, @FilePrefix("maven") OutputFiles outputFi
 	}
 
 	private ProcessResult run(OutputFiles outputFiles, String version) throws Exception {
-		return ProcessStarters.maven(Helper.getJavaHome("8").orElseThrow(TestAbortedException::new)) //
+		return ProcessStarters.maven(Helper.getJavaHome("17").orElseThrow(TestAbortedException::new)) //
 				.workingDir(copyToWorkspace(Projects.VINTAGE, workspace)) //
 				.addArguments("clean", "test", "--update-snapshots", "--batch-mode") //
 				.addArguments(localMavenRepo.toCliArgument(), "-Dmaven.repo=" + MavenRepo.dir()) //