[merlish]

They're planning both. Reference counting/bump pointer allocation in-frame for temp stuff & no GC & manual memory management for the upcoming high-performance restricted C# subset data-oriented jobs code, and for full-fat real C# code they're slowly working to clean up their (C++ coded) runtime so that a non-conservative garbage collector can work.

Re. Boehm, that was the garbage collector Mono shipped until they wrote SGen some years back.

I'm quite excited by the work they're doing on performance. It looks great.