Two possibilities to setup work (root, gcc, python, atlas crap) on tier3:

Insert in .sh file to be sourced at login time

export ATLAS_LOCAL_ROOT_BASE=/cvmfs/atlas.cern.ch/repo/ATLASLocalRootBasesource

${ATLAS_LOCAL_ROOT_BASE}/user/atlasLocalSetup.sh

alias setupATLAS='source  ${ATLAS_LOCAL_ROOT_BASE}/user/atlasLocalSetup.sh'

#this set up python

localSetupPython --pythonVersion=2.6.5-x86_64-slc5-gcc43

#this set up root 5.32

source /cvmfs/atlas.cern.ch/repo/ATLASLocalRootBase/x86_64/root/5.32.00-x86_64-slc5-gcc4.3/bin/thisroot.sh
#this setup gcc compiler

source /cvmfs/atlas.cern.ch/repo/ATLASLocalRootBase/x86_64/Gcc/gcc435_x86_64_slc5/setup.sh 

One can also set up using asetup the usual athena crap...

  • Using afs (deprecated)

source /afs/cern.ch/sw/lcg/external/gcc/4.3.2/x86_64-slc5/setup.sh
cd /afs/cern.ch/sw/lcg/app/releases/ROOT/5.32.00/x86_64-slc5-gcc43-opt/root
source bin/thisroot.sh
cd - 

 P.S. Note the versions are selected using the various directories