C++

Actually, no. The first version of GWS was based on boa and written in strict C.

Listen to Paul. He knows.

oh like you'd know!

(kidding) :-)

I don't think the problem was with Python. It seems that the problem was that their code wasn't very good.

It's worth pointing out that there are lots of good tools available now (which were not available then) which make Python an excellent choice for high performance systems.

I will take my Python zealot hat off now. You just raised my hackles slightly, is all :-)

Scaling a website and scaling a search engine are two very different things. Python websites are OK, Python search engines... well: http://whoosh.ca/blog/fools_errand

Rails

Just kidding - no idea