The default Gnu compilers on the CSC clusters is 4.4, but sometimes codes require a more recent compiler, 4.8 being common.
You can use Gnu 4.8 by typing:
You can verify this worked by typing
and you will see something like this: gcc version 4.8.2 20140120 (Red Hat 4.8.2-15) (GCC)
Also, if you need a more recent 'cmake' than 2.6, you can simply type
to use a more recent version.