[nemothekid]

>It’s developed and supported exclusively by one huge web company, and they may decide to deprecate and replace it in a few years as their technical needs change or its core engineers move on to new projects.

Thats an interesting sentiment. The exact same could be said for languages like Go (Google), C# (Microsoft), Rust (Mozilla) and platforms like NodeJS (Joyent). In any case it doesn't seem like too much of a worry. Cassandra came from Facebook, and was well done enough that another company came in and picked up development when Facebook left it.

[jimhart3000]

Objective-C as well.

[Delmania]

Nitpick, C# is an ECMA standard that has a non proprietary implementation (Mono). I realize the best implementation is the CLR provided by Microsoft, but is feasible that should Microsoft abandon C#, others could pick it up.

[cafard]

I'm pretty sure that I remember Objective-C (under gcc) from way back.