In order to use icc/icpc, you will have to add some lines to your login scripts (,cshrc for csh/tcsh, .bashrc for bash).
source source /nfs/guille/a2/rh80apps/intel/current/bin/compilervars.csh intel64
source source /nfs/guille/a2/rh80apps/intel/current/bin/compilervars.sh intel64
You must also export an environment variable telling the system where to find the license. For our license, you need to export the following variable:
setenv INTEL_LICENSE_FILE email@example.com
To invoke the installed compilers
To get help, append the -help option or precede with the man command.
Some final comments. The Intel compilers are significantly more standards compliant than gcc. This means that a lot of your code which uses non-standard extensions, will no longer compile and/or function correctly. This is due to what the standard refers to as "implementation dependent behavior".