Performance gains of up to approximately 30% over gcc 3.2. Optional Fortran compiler vs. g77, which translates into C and compiles with GCC. GCC compatibility mode. 64-bit support (Intel Itanium only) ...
There was a time when trying to learn to write low-level driver or kernel code was hard. You really needed two machines: one to work with, and one to screw up over and over again until you got it ...