It's the International Music Score Library Project. I just landed onto this site which works like Project Gutenberg (w/c shares public domain ebooks). I read it was down for quite a while and just this June it's again back up. It has a enormous library of public domain scores and from what I have browsed so far (which is I believe just the tip of an iceberg) are mostly classical scores. So, hooray!

Anyway, just sharing. Perhaps you guys have known about it before it even temporarily closed, eh?

keira