A survey of the many jit projects. Parrot using llvm instead of own jit.

Comment from Allison Randal, Chief Architect of the Parrot project:

LLVM provides a set of tools that look promising for allowing us to quickly develop a JIT, taking advantage of the platforms they already support. (Note that LLVM currently has limited support for Windows, so it's not quite there on all our target platforms.) The plan is to develop a rapid prototype of an LLVM-based JIT, to see if it might work as the primary Parrot JIT, or perhaps as one of several JIT strategies.

So it looks more like the Parrot team is going to try out LLVM and see if it meets their needs. Their current JIT seems to be unstable and they want to evaluate alternatives.

The list of good jit/great jit characteristics on this page: https://trac.parrot.org/parrot/wiki/JITRewrite is especially interesting. For example, the ability to "output generated machine code to an executable or object file" is really great. As I understand it, it is the Mono JIT's -aot option that allows the Unity team to deploy .NET games on the iPhone.