Updated the documentation with Mac OS X specific information.

README.md

@@ -1,2 +1,54 @@
 # Common Lisp SDL2 tutorials
 Adapted from http://lazyfoo.net/tutorials/SDL/
+
+
+## Installing the SDL2 Libraries
+
+  The tutorial requires that SDL2, SDL2 Image, and SDL2 TTF are installed before
+  running the examples.
+
+### Mac OS X
+
+Mac OS X requires each library to be downloaded and copied to
+$HOME/Library/Frameworks or /Library/Frameworks.
+
+ Library Name | Download Link
+ ------------ | -------------
+ SDL2         | https://www.libsdl.org/download-2.0.php
+ SDL2 Image   | https://www.libsdl.org/projects/SDL_image
+ SDL2 TTF     | https://www.libsdl.org/projects/SDL_ttf
+
+Running the tutorials will cause Catalina to report that the framework cannot be
+opened because the developer cannot be verified. The workaround for this problem
+is the following:
+
+1. Navigate to System Preferences -> Security & Privacy -> General on the Mac
+
+2. Run repl.sh
+
+3. When the dialog appears about the developer not being verified, click the
+"Cancel" button.
+
+4. Examine the Security & Privacy screen for a button called "Allow Anyway" for
+the framework. Click the "Allow Anyway" button with the identified framework.
+
+5. The verification dialog will now appear a second time, but there will be an
+option to "Open" the framework. Click "Open".
+
+6. Repeat steps 3 through 5 for the different frameworks.
+
+### Linux
+
+The SDL2 libraries can be installed on a Debian based system with the command
+below.
+
+	apt install libsdl2-2.0 libsdl2-image-2.0 libsdl2-ttf-2.0
+
+
+## Running the Examples
+
+A repl.sh script is provided that loads SDL2-TUTORIAL with quicklisp and then
+starts up a swank thread on port 4005 for repl connections.
+
+	1. ./repl.sh
+	2. (sdl2-tutorial:main #'sdl2-tutorial-1:main)