"The dragonegg GCC plugin can host itself! Dragonegg lets you use the LLVM optimizers with GCC-4.5, much like llvm-gcc, but unlike llvm-gcc does not involve modifying GCC, thanks to the new GCC plugin infrastructure (currently one small patch is required). We built all of GCC-4.5, LLVM and dragonegg with dragonegg, then used the resulting binaries to build them all again. Why? Because we love to build! And because this was a great way of checking that nothing was miscompiled. The final dragonegg plugin was fully functional, successfully passing the entire dragonegg test suite."