[anonoholic]

> They take the XenServer sources, remove licensing restrictions

Um, how exactly? You generally can't take software with licence X, and republish it with license Y...

[yjftsjthsd-h]

I don't know about this case, but it's not that rare to see source code published under ex. Apache 2 while official binaries are proprietary or something (see ex. Caddy), in which case it's easy enough to just grab the source, enable all features, and distribute the result. Arguably similar to what AWS did with Elasticsearch recently.

[stordoff]

I believe OP is referring to the feature restrictions that Citrix put on the free version, rather than changing the licence of the code.