Most mainstream languages are "done" in the way that matters here. Not "done" in the sense of "not receiving new features anymore", but in the sense that you co

Most mainstream languages are "done" in the way that matters here. Not "done" in the sense of "not receiving new features anymore", but in the sense that you could switch their implementations to maintenance mode today and they'd remain useful for a long time. Easily visible with languages where people do indeed keep using old versions for whatever reason.