Hi, I'm totally new with centos...we have a cluster in our labo with centos oscar. The gcc which was provided with the release is gcc41 and gfortran41. There are packages for gcc44 and gfortran44. I have installed them. But the gcc is not a link to gcc41 or gcc44. it is just an executable. idem for gfortran. So which is the good way on centOS to choose the gcc44 and gfortran44 per default. Thx a lot! Best regards, Guillaume