Java(TM) 2 Platform Standard Edition from Sun
Tools for developing and testing programs written in the Java programming language from Sun
The GNU Compiler for the JavaTM Programming Language
GCJ is a portable, optimizing, ahead-of-time compiler for the Java Programming Language.
Excelsior JET Evaluation Package
Excelsior JET 5.0 supports J2SE 5.0 Update 11 (1.5.0_11) out-of-the-box.
Toba A Java-to-C Translator
Toba translates Java class files into C source code. This allows the construction of directly executable programs that avoid the overhead of interpretation. Toba deals with stand-alone applications, not applets.