CLISP is a portable ANSI Common Lisp implementation and development environment by Bruno Haible. Interpreter, compiler, debugger, CLOS, MOP, FFI, Unicode, sockets, CLX. UI in English, German, French, Spanish, Dutch, Russian, and Danish.
Fastjar is an implementation of Sun's jar utility that comes with the JDK, written entirely in C, and runs in a fraction of the time while being 100% feature compatible.
An initiative to support and extend the Free Pascal compiler on the BeOS, and create a objects library to allow the creation of graphical user applications.
wspacegen is an interactive IDE for programing with whitespace (http://compsoc.dur.ac.uk/whitespace/). So it's possible to create .ws code relative easily and debug it as well. But attention, you'll addicted to it (-:
orange is a new object oriented programing language, combining features from objective c, java and scheme. it's main targets are compactness, efficency and rapid prototyping.