Mono is not Microsoft..NET technology, but Mono is not. Mono is an open source implementation of the ECMA-334 and ECMA-335 standards. Yes, they came from Microsoft, but Mono itself is not Microsoft technology.
Not that Mono is a language, of course - C # is a language. But then the languages are not really open-source or not. There are implementations.
, , , #, Java. , , Java ( #), .