It has been called CIL close to a decade now..

The first edition of ECMA-335 was published December 2001, so now almost two!

Yep, that was the most surprising thing to me. In my circles people have just continued calling it MSIL all this time and I’ve never questioned it or needed to research anything MSIL related so I guess it slipped past me all this time. Hence the “what the hell!”

MSIL is Microsoft's implementation of the open standard CIL, which has been open for over a decade, and is how Mono even works.

That explains a lot.