Optionally, the new alias(es) may be added to your home/user/.bashrc and used called when needed:
alias of21Local='. installPath/OpenFOAM/OpenFOAM-2.1.x-Local/etc/bashrc.Xeon'
alias of23Opteron='. installPath/OpenFOAM/OpenFOAM-2.3.x/etc/bashrc.Opteron'
alias of23LocalXeon='. installPath/OpenFOAM/OpenFOAM-2.3.x/etc/bashrc.Xeon'