diff --git a/.github/workflows/linux-builder-update.yml b/.github/workflows/linux-builder-update.yml
index 8ea8ee4..e1e86b5 100644
--- a/.github/workflows/linux-builder-update.yml
+++ b/.github/workflows/linux-builder-update.yml
@@ -12,11 +12,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash x86-64-unknown-linux-builder/build-and-push.bash
       - name: Send alert on failure
@@ -39,11 +46,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash x86-64-unknown-linux-builder-with-libressl-3.5.3/build-and-push.bash
       - name: Send alert on failure
@@ -66,11 +80,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash x86-64-unknown-linux-builder-with-libressl-3.7.2/build-and-push.bash
       - name: Send alert on failure
@@ -93,11 +114,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash x86-64-unknown-linux-builder-with-openssl_1.1.1q/build-and-push.bash
       - name: Send alert on failure
@@ -120,11 +148,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash x86-64-unknown-linux-builder-with-openssl_1.1.1t/build-and-push.bash
       - name: Send alert on failure
@@ -147,11 +182,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash x86-64-unknown-linux-builder-with-openssl_3.0.7/build-and-push.bash
       - name: Send alert on failure
@@ -174,11 +216,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash x86-64-unknown-linux-builder-with-openssl_3.1.0/build-and-push.bash
       - name: Send alert on failure
@@ -201,11 +250,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash x86-64-unknown-linux-builder-with-pcre/build-and-push.bash
       - name: Send alert on failure
@@ -282,3 +338,44 @@ jobs:
           type: stream
           topic: ${{ github.repository }} scheduled job failure
           content: ${{ github.server_url}}/${{ github.repository }}/actions/runs/${{ github.run_id }} failed.
+
+  prune-untagged-builder-images:
+    needs:
+      - send-linux-builders-updated-event
+
+    name: Prune untagged builder images
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        image:
+          - shared-docker-ci-x86-64-unknown-linux-builder
+          - shared-docker-ci-x86-64-unknown-linux-builder-with-libressl-3.5.3
+          - shared-docker-ci-x86-64-unknown-linux-builder-with-libressl-3.7.2
+          - shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_1.1.1q
+          - shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_1.1.1t
+          - shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_3.0.7
+          - shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_3.1.0
+          - shared-docker-ci-x86-64-unknown-linux-builder-with-pcre
+
+    steps:
+      - name: Prune
+        # v4.1.1
+        uses: actions/delete-package-versions@0d39a63126868f5eefaa47169615edd3c0f61e20
+        with:
+          package-name: ${{ matrix.image }}
+          package-type: 'container'
+          min-versions-to-keep: 1
+          delete-only-untagged-versions: 'true'
+      - name: Send alert on failure
+        if: ${{ failure() }}
+        uses: zulip/github-actions-zulip/send-message@b62d5a0e48a4d984ea4fce5dd65ba691963d4db4
+        with:
+          api-key: ${{ secrets.ZULIP_SCHEDULED_JOB_FAILURE_API_KEY }}
+          email: ${{ secrets.ZULIP_SCHEDULED_JOB_FAILURE_EMAIL }}
+          organization-url: 'https://ponylang.zulipchat.com/'
+          to: notifications
+          type: stream
+          topic: ${{ github.repository }} scheduled job failure
+          content: ${{ github.server_url}}/${{ github.repository }}/actions/runs/${{ github.run_id }} failed.
diff --git a/.github/workflows/release-a-library-update.yml b/.github/workflows/release-a-library-update.yml
index 6f661a4..d080e38 100644
--- a/.github/workflows/release-a-library-update.yml
+++ b/.github/workflows/release-a-library-update.yml
@@ -13,11 +13,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Docker login
+      - name: Login to DockerHub
         run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+      - name: Login to GitHub Container Registry
+        # v2.2.0
+        uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push
         run: bash release-a-library/build-and-push.bash
       - name: Send alert on failure
@@ -31,3 +38,30 @@ jobs:
           type: stream
           topic: ${{ github.repository }} scheduled job failure
           content: ${{ github.server_url}}/${{ github.repository }}/actions/runs/${{ github.run_id }} failed.
+
+  prune-untagged-images:
+    needs:
+      - release-a-library
+
+    name: Prune untagged images
+    runs-on: ubuntu-latest
+    steps:
+      - name: Prune
+        # v4.1.1
+        uses: actions/delete-package-versions@0d39a63126868f5eefaa47169615edd3c0f61e20
+        with:
+          package-name: 'shared-docker-ci-release-a-library'
+          package-type: 'container'
+          min-versions-to-keep: 1
+          delete-only-untagged-versions: 'true'
+      - name: Send alert on failure
+        if: ${{ failure() }}
+        uses: zulip/github-actions-zulip/send-message@b62d5a0e48a4d984ea4fce5dd65ba691963d4db4
+        with:
+          api-key: ${{ secrets.ZULIP_SCHEDULED_JOB_FAILURE_API_KEY }}
+          email: ${{ secrets.ZULIP_SCHEDULED_JOB_FAILURE_EMAIL }}
+          organization-url: 'https://ponylang.zulipchat.com/'
+          to: notifications
+          type: stream
+          topic: ${{ github.repository }} scheduled job failure
+          content: ${{ github.server_url}}/${{ github.repository }}/actions/runs/${{ github.run_id }} failed.
diff --git a/actionlint/build-and-push.bash b/actionlint/build-and-push.bash
index 7751fa5..66bde75 100644
--- a/actionlint/build-and-push.bash
+++ b/actionlint/build-and-push.bash
@@ -4,12 +4,19 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 NAME="ponylang/shared-docker-ci-actionlint"
 TODAY=$(date +%Y%m%d)
 DOCKERFILE_DIR="$(dirname "$0")"
 
+# DockerHub
+docker build --pull -t "${NAME}:${TODAY}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TODAY}"
+
+# GitHub Container Registry
+NAME="ghcr.io/${NAME}"
 docker build --pull -t "${NAME}:${TODAY}" "${DOCKERFILE_DIR}"
 docker push "${NAME}:${TODAY}"
diff --git a/release-a-library/build-and-push.bash b/release-a-library/build-and-push.bash
index 98cf9d0..ba1a01e 100644
--- a/release-a-library/build-and-push.bash
+++ b/release-a-library/build-and-push.bash
@@ -4,23 +4,46 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
 
+## DockerHub
+
+# built from ponyc release tag
+NAME="ponylang/shared-docker-ci-release-a-library"
+FROM_TAG=release-alpine
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" \
+  "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from ponyc latest tag
+FROM_TAG=alpine
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" \
+  "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
 # built from ponyc release tag
+NAME="ghcr.io/ponylang/shared-docker-ci-release-a-library"
 FROM_TAG=release-alpine
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t ponylang/shared-docker-ci-release-a-library:"${TAG_AS}" \
+  -t "${NAME}:${TAG_AS}" \
   "${DOCKERFILE_DIR}"
-docker push ponylang/shared-docker-ci-release-a-library:"${TAG_AS}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from ponyc latest tag
 FROM_TAG=alpine
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t ponylang/shared-docker-ci-release-a-library:"${TAG_AS}" \
+  -t "${NAME}:${TAG_AS}" \
   "${DOCKERFILE_DIR}"
-docker push ponylang/shared-docker-ci-release-a-library:"${TAG_AS}"
+docker push "${NAME}:${TAG_AS}"
diff --git a/x86-64-unknown-linux-builder-with-libressl-3.5.3/build-and-push.bash b/x86-64-unknown-linux-builder-with-libressl-3.5.3/build-and-push.bash
index 591ddab..9676ee2 100644
--- a/x86-64-unknown-linux-builder-with-libressl-3.5.3/build-and-push.bash
+++ b/x86-64-unknown-linux-builder-with-libressl-3.5.3/build-and-push.bash
@@ -4,22 +4,44 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
-IMAGE="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-libressl-3.5.3"
+
+## DockerHub
+
+NAME="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-libressl-3.5.3"
+
+# built from x86-64-unknown-linux-builder release tag
+FROM_TAG=release
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from x86-64-unknown-linux-builder latest tag
+FROM_TAG=latest
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
+NAME="ghcr.io/ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-libressl-3.5.3"
 
 # built from x86-64-unknown-linux-builder release tag
 FROM_TAG=release
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from x86-64-unknown-linux-builder latest tag
 FROM_TAG=latest
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
diff --git a/x86-64-unknown-linux-builder-with-libressl-3.7.2/build-and-push.bash b/x86-64-unknown-linux-builder-with-libressl-3.7.2/build-and-push.bash
index 5555657..998ce07 100644
--- a/x86-64-unknown-linux-builder-with-libressl-3.7.2/build-and-push.bash
+++ b/x86-64-unknown-linux-builder-with-libressl-3.7.2/build-and-push.bash
@@ -4,22 +4,44 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
-IMAGE="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-libressl-3.7.2"
+
+## DockerHub
+
+NAME="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-libressl-3.7.2"
+
+# built from x86-64-unknown-linux-builder release tag
+FROM_TAG=release
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from x86-64-unknown-linux-builder latest tag
+FROM_TAG=latest
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
+NAME="ghrc.io/ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-libressl-3.7.2"
 
 # built from x86-64-unknown-linux-builder release tag
 FROM_TAG=release
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from x86-64-unknown-linux-builder latest tag
 FROM_TAG=latest
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
diff --git a/x86-64-unknown-linux-builder-with-openssl_1.1.1q/build-and-push.bash b/x86-64-unknown-linux-builder-with-openssl_1.1.1q/build-and-push.bash
index 5cd14f2..dd31b3b 100644
--- a/x86-64-unknown-linux-builder-with-openssl_1.1.1q/build-and-push.bash
+++ b/x86-64-unknown-linux-builder-with-openssl_1.1.1q/build-and-push.bash
@@ -4,22 +4,44 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
-IMAGE="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_1.1.1q"
+
+## DockerHub
+
+NAME="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_1.1.1q"
+
+# built from x86-64-unknown-linux-builder release tag
+FROM_TAG=release
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from x86-64-unknown-linux-builder latest tag
+FROM_TAG=latest
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
+NAME="ghcr.io/ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_1.1.1q"
 
 # built from x86-64-unknown-linux-builder release tag
 FROM_TAG=release
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from x86-64-unknown-linux-builder latest tag
 FROM_TAG=latest
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
diff --git a/x86-64-unknown-linux-builder-with-openssl_1.1.1t/build-and-push.bash b/x86-64-unknown-linux-builder-with-openssl_1.1.1t/build-and-push.bash
index 2472465..9d626bc 100644
--- a/x86-64-unknown-linux-builder-with-openssl_1.1.1t/build-and-push.bash
+++ b/x86-64-unknown-linux-builder-with-openssl_1.1.1t/build-and-push.bash
@@ -4,22 +4,44 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
-IMAGE="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_1.1.1t"
+
+## DockerHub
+
+NAME="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_1.1.1t"
+
+# built from x86-64-unknown-linux-builder release tag
+FROM_TAG=release
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from x86-64-unknown-linux-builder latest tag
+FROM_TAG=latest
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
+NAME="ghcr.io/ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_1.1.1t"
 
 # built from x86-64-unknown-linux-builder release tag
 FROM_TAG=release
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from x86-64-unknown-linux-builder latest tag
 FROM_TAG=latest
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
diff --git a/x86-64-unknown-linux-builder-with-openssl_3.0.7/build-and-push.bash b/x86-64-unknown-linux-builder-with-openssl_3.0.7/build-and-push.bash
index 53cf066..72c206e 100644
--- a/x86-64-unknown-linux-builder-with-openssl_3.0.7/build-and-push.bash
+++ b/x86-64-unknown-linux-builder-with-openssl_3.0.7/build-and-push.bash
@@ -4,22 +4,44 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
-IMAGE="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_3.0.7"
+
+## DockerHub
+
+NAME="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_3.0.7"
+
+# built from x86-64-unknown-linux-builder release tag
+FROM_TAG=release
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from x86-64-unknown-linux-builder latest tag
+FROM_TAG=latest
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
+NAME="ghcr.io/ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_3.0.7"
 
 # built from x86-64-unknown-linux-builder release tag
 FROM_TAG=release
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from x86-64-unknown-linux-builder latest tag
 FROM_TAG=latest
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
diff --git a/x86-64-unknown-linux-builder-with-openssl_3.1.0/build-and-push.bash b/x86-64-unknown-linux-builder-with-openssl_3.1.0/build-and-push.bash
index 8086fc2..c4c4ea3 100644
--- a/x86-64-unknown-linux-builder-with-openssl_3.1.0/build-and-push.bash
+++ b/x86-64-unknown-linux-builder-with-openssl_3.1.0/build-and-push.bash
@@ -4,22 +4,44 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
-IMAGE="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_3.1.0"
+
+## DockerHub
+
+NAME="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_3.1.0"
+
+# built from x86-64-unknown-linux-builder release tag
+FROM_TAG=release
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from x86-64-unknown-linux-builder latest tag
+FROM_TAG=latest
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
+NAME="ghcr.io/ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-openssl_3.1.0"
 
 # built from x86-64-unknown-linux-builder release tag
 FROM_TAG=release
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from x86-64-unknown-linux-builder latest tag
 FROM_TAG=latest
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t "${IMAGE}:${TAG_AS}" "${DOCKERFILE_DIR}"
-docker push "${IMAGE}:${TAG_AS}"
+  -t "${NAME}:${TAG_AS}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
diff --git a/x86-64-unknown-linux-builder-with-pcre/build-and-push.bash b/x86-64-unknown-linux-builder-with-pcre/build-and-push.bash
index b8da3b1..5137ac4 100644
--- a/x86-64-unknown-linux-builder-with-pcre/build-and-push.bash
+++ b/x86-64-unknown-linux-builder-with-pcre/build-and-push.bash
@@ -4,23 +4,48 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
 
+## DockerHub
+
+NAME="ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-pcre"
+
+# built from x86-64-unknown-linux-builder release tag
+FROM_TAG=release
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" \
+  "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from x86-64-unknown-linux-builder latest tag
+FROM_TAG=latest
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" \
+  "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
+NAME="ghcr.io/ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-pcre"
+
 # built from x86-64-unknown-linux-builder release tag
 FROM_TAG=release
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-pcre:"${TAG_AS}" \
+  -t "${NAME}:${TAG_AS}" \
   "${DOCKERFILE_DIR}"
-docker push ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-pcre:"${TAG_AS}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from x86-64-unknown-linux-builder latest tag
 FROM_TAG=latest
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-pcre:"${TAG_AS}" \
+  -t "${NAME}:${TAG_AS}" \
   "${DOCKERFILE_DIR}"
-docker push ponylang/shared-docker-ci-x86-64-unknown-linux-builder-with-pcre:"${TAG_AS}"
+docker push "${NAME}:${TAG_AS}"
diff --git a/x86-64-unknown-linux-builder/build-and-push.bash b/x86-64-unknown-linux-builder/build-and-push.bash
index 77da9cc..42af120 100644
--- a/x86-64-unknown-linux-builder/build-and-push.bash
+++ b/x86-64-unknown-linux-builder/build-and-push.bash
@@ -4,23 +4,46 @@ set -o errexit
 set -o nounset
 
 #
-# *** You should already be logged in to DockerHub when you run this ***
+# *** You should already be logged in to DockerHub
+#     and GitHub Container Registry when you run this ***
 #
 
 DOCKERFILE_DIR="$(dirname "$0")"
 
+## DockerHub
+
+# built from ponyc release tag
+NAME="ponylang/shared-docker-ci-x86-64-unknown-linux-builder"
+FROM_TAG=release-alpine
+TAG_AS=release
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" \
+  "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+# built from ponyc latest tag
+FROM_TAG=alpine
+TAG_AS=latest
+docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
+  -t "${NAME}:${TAG_AS}" \
+  "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TAG_AS}"
+
+## GitHub Container Registry
+
 # built from ponyc release tag
+NAME="ghcr.io/ponylang/shared-docker-ci-x86-64-unknown-linux-builder"
 FROM_TAG=release-alpine
 TAG_AS=release
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t ponylang/shared-docker-ci-x86-64-unknown-linux-builder:"${TAG_AS}" \
+  -t "${NAME}:${TAG_AS}" \
   "${DOCKERFILE_DIR}"
-docker push ponylang/shared-docker-ci-x86-64-unknown-linux-builder:"${TAG_AS}"
+docker push "${NAME}:${TAG_AS}"
 
 # built from ponyc latest tag
 FROM_TAG=alpine
 TAG_AS=latest
 docker build --pull --build-arg FROM_TAG="${FROM_TAG}" \
-  -t ponylang/shared-docker-ci-x86-64-unknown-linux-builder:"${TAG_AS}" \
+  -t "${NAME}:${TAG_AS}" \
   "${DOCKERFILE_DIR}"
-docker push ponylang/shared-docker-ci-x86-64-unknown-linux-builder:"${TAG_AS}"
+docker push "${NAME}:${TAG_AS}"