They buy some of the music, but some was done by Geoff Scott and others, in-house.
As for the tools they use... it's a lot, actually. Besides the ones already mentioned, I believe they use Granny 3D for animation and Havok for certain effects (e.g. crumbling walls and such). They also use some package for developing particle effects, but I can't remember what it is.
On the programming side, they use Visual Studio to write and debug code, and Perforce for revision control.
Khafar