The LLVM Developer group have announced the release of version 2.2 of LLVM, an open source compiler infrastructure, which supports compilation of C, C++, Fortran, Objective C and Ada programs.
If you'd like to try it out before downloading, they even have an online demo available.
Sun Microsystems have a new article up on their developer website on Getting Started with Sun Studio Software. Sun Studio is a developer environment for both Solaris and Linux, and provides compilers for C, C++ and Fortran.