Languages for the Java VM - A list of tools for programming to the Java virtual machine using a language other than Java itself. (Robert Tolksdorf) - http://www.robert-tolksdorf.de/vmlanguages.html
Compiling the Java Programming Language - Issues related to compiling Java into native (object) code. Treats why, compiler architecture, links (Java compiling, compiling generally), frontend and infrastructure software. - http://www.bearcave.com/software/java/java_compiler.html