Big Shot Games such as Halo, Counter Strike etc..

I was wondering what language or tools they use to make BIG games such as Halo and CS (counter strike).

Do they use different tools to make it on PC then on PS2 etc or same?

Which Language is it, I presume its more C++ and Assembly? Or they use big ready made or specifically made programs?

Just curious lol as I have no idea...

I don't know many of the details here, but I do know there are a variety of graphics libraries that can be used on PC, Mac, PS2, Xbox, etc. Some even work on all 4 and more. 3dstate.com is a good example.I know some companies will design everything on their own in order to get their game working "just right". For instance, NaughtDogg used Allegro Common Lisp to write their own implementation of Lisp (called GOAL) to create their Crash Bandicoot games for the PS2. C++ is a popular choice in game development regardless of the platform, however, NBA Jam for the Sega Genesis (I loved that game back when I was like 8 years old) was written entirely in assembly -- I can't imagine this being done in the world of today.