A full system emulator like QEMU that's built as a compiler generator. The goal is to build new interpretors and stage 1 JITs at runtime that are tailored to specific supervisor states to give good low latency performance before code hits a real big boy JIT.

Targeting game consoles at the moment because of how sensitive those emulators are to latency as well as raw perf, but better a ARM Android emulator is one of the end goals.