[krapp]

Doesn't HN use a proprietary fork of Arc?

I've never been entirely certain what the relationship is between YCombinator and the Arc community, if any, but one experimental and partially black-boxed forum doesn't signal a mature language, just one adequate to a particular task.

What else have people done in Arc?

[Immortalin]

Arc has served as material for a lot of speculative blogposts and helped create buzz for the lisp community.

[brudgers]

Being a Lisp, I'm not exactly sure what would constitute a proprietary fork. Furthering my uncertainty is that it [Anarki] is built on Racket and that kinda makes it hard to say one implementation is forked from another.

Anyway, I didn't intend to claim that Arc was a mature language.