The libjit library implements Just-In-Time compilation functionality. Unlike other JIT's, this one is designed to be independent of any particular virtual machine bytecode format or language. The hope is that Free Software projects can get a leg-up on proprietry VM vendors by using this library rather than spending large amounts of time writing their own JIT from scratch. This JIT is also designed to be portable to multiple archictures. If you run libjit on a machine for which a native code generator is not yet available, then libjit will fall back to interpreting the code. This way, you don't need to write your own interpreter for your bytecode format if you don't want to. WWW: http://www.gnu.org/software/libjit/