.NET

Usually said to be from network. Called in early press announcements Next Generation Windows Services before this name was chosen. According to Justin Grant, who was part of the team on the Microsoft campus, the name was chosen because it:

mirrored the domain suffix [.net] of (at the time) every ISP, so was intended to remind users that "web-enabling your software" was the core scenario being targetted by this work

was more approachable to business types and CIOs than geekier names like "Universal Runtime" or "COM+ 2.0"

had practical benefits like: being short, easy to spell, globalized well, could leverage already-owned domain names for every Microsoft product, etc.

actually passed legal/trademark review (surprisingly difficult!)

So it was intended to mean something, but more so by connotation rather than directly abbreviating or describing something.