A CTP — publicly available, contents-may-settle, pre-beta preview — of the aforementioned Roslyn C#/VB structurally open compilers has been released.
So far, syntax trees, flow analysis and beyond-compilation reasoning such as “what type or thing would this be if I placed it into this location” seems to be almost fully available, although code generation is still missing in chunks. Comes with some interesting documentation. The project overview is so far a real page-turner and it’s interesting how they handle whitespace/comments round-tripping and partial compile error recovery and reporting.
It’s exciting to see Microsoft take the step of repaving Visual Studio’s tooling on top of this. Here’s hoping they start a trend.