The GCC JIT support led by David Malcolm at Red Hat has finally landed into mainline GCC meaning it will be part of next year's GCC 5 release. GCC 5 already has a ton of improvements and new functionality while it still seems to be growing by the day with exciting additions. The GCC JIT support allows an embedded library by GPL applications for those wishing to leverage GCC for just-in-time compilation abilities, similar to what LLVM has long offered.
The GCC JIT support is completely embeddable within other applications, can be used by bytecode interpreters and other programs for generating native and optimized machine code at run-time, has been used for an experimental Python compiler, and all around is quite an interesting addition to GCC with libgccjit.so.
The GCC JIT support was merged yesterday to mainline and represents more than one year of work by David Malcolm and others.