[__rvx86]

I do. MS-Java still sticks in my craw to this day. Don’t get me started...

.NET has been an open standard since 2003—the Mono-Project is a nearly complete open-source .NET framework for UNIX/Linux, with the exception of Windows-specific components. (Windows Forms, OTOH, is included)

As I recall, MFC was ported only to Freescale-based Macintosh: 68k and PowerPC.

Not sure about UNIX/Linux support—the closest thing I can recall was the framework that MS used to port Internet Explorer to UNIX, which wrapped MFC: MainWin XDE...

[SecondAmendment]

Okay, so you have a good idea of what they have done in the past, but the proof of them doing it this time is their lack of supporting swift.

Over time Apple will shift APIs over to Swift, while those using Objective-C will be told by their bosses not to bother moving to Swift, and voila, MS lock in!