A reverse engineering suite (decompiler, editor, debugger and more)
Manifold is a Java compiler plugin, features include Metaprogramming
Learn Java the easy way!
Lightweight IDE for Java
JPHP - an implementation of PHP on Java VM
Best IDE for Beginners
Performance and Productivity at Scale
Java Bytecode Viewer & Decompiler
Problemless Grammar and Parser in Java
Pure Trait-based Programming on the Java Platform
a DSL for type systems, reduction rules, interpreters for Xtext langs