I was recently discussing functional programming with a co-worker. While the two of us both agreed that FP has some obvious benefits (simpler code, easier to reason about mathematically, etc.), we both wondered whether or not it is or will ever be used in commerical software.
I know there are a number of open source and academic projects that are written functionally (e.g. I've seen this question on Stack Overflow) but I'm wondering if anyone can list some other commercial software that is written, at least in part, in a functional language (and what language).