Cibyl is a programming environment and binary translator that allows compiled C programs to execute on J2ME-capable phones. Cibyl uses GCC to compile the C programs to MIPS binaries, and these are then recompiled into Java bytecode.
NestedVM provides binary translation for Java Bytecode. This is done by having GCC compile to a MIPS binary which is then translated to a Java class file. Hence any application written in C, C++, Fortran, or any other language supported by GCC can be run in 100% pure Java with no source changes.