Looks like work on this began at the latest in 2014, with regular work up to the present. I'm not sure how it fits in with the author's other projects but it seems like there's a lot of integration.
I was able to just skip over the trap calls in the Metrowerks runtime code for very the simplest programs, but in 2012 I added a real trap dispatcher and NewPtr/DisposePtr to implement malloc(). Virtual screen hardware and basic rectangle drawing appeared in 2013. But yeah, 2014 is when things started to get interesting.
Virtually all of my major projects are involved somehow: the Mac frontends are MacRelix. Freemount is used to serve files over a socket pair (since emulated code can't access the native file system). And the launch script is V code.