If you need to find out which "flavour" (or distro) Linux you are using just type the following command at the prompt:
[definenull@hm1446 ~]$ cat /etc/*-release
Red Hat Enterprise Linux Server release 5.3 (Tikanga)
This might not work on all distros, so a more general approach would be running the command:
[definenull@hm1446 ~]$ lsb_release -a
LSB Version: :core-3.1-ia32:core-3.1-noarch:graphics-3.1-ia32:graphics-3.1-noarch
Distributor ID: RedHatEnterpriseServer
Description: Red Hat Enterprise Linux Server release 5.3 (Tikanga)