Our main machines are Linux 64bit gcc 4.1 however we keep Linux 32bit gcc 3.4 up to date as well for some legacy machines. We also have some OSX machines, and we always download the same version of Win32 (vc8) and archive it, though have rarely actually needed it.

We could survive on Linux 64bit gcc 4.1 and OSX

At home I use Linux 64bit gcc4.2 and Win32 (vc8) on my Vista32 laptop.

cheers,

Peter B