[DannyBee]

In some ways, #2 is sad to me. Don't get me wrong, I have worked a ton on LLVM and love it.

But at least when i was there, IBM's interprocedural middle-end (TPO) was some of the nicest and well structured C++ compiler code i had seen in a long time. It was well written, well commented, and well architected.

[IainIreland]

It may have changed since I left, but my understanding as of a few years ago was that IBM was replacing the front-end with Clang but continuing to use TPO (at least for now).