BB10 is probably the most stable we've had as of yet (in the sense that the debugger now largely works and I was able to have it run GMLive code for the first time without the runner hard crashing)
(shown: REPL using GMLive, gml_string, and an advanced chat/command log extension that I've not released)
but it's only been a few days so I don't have much else but live_execute_string/Snippet API working yet. It's unclear whether it is worth releasing in this state.