Linux is the world's most popular 'alternative' operating system, and is the best known variant of Unix. While the base Linux operating system shell is free, the best way to get a start on Linux networking is to buy a Linux operating system from one of the main Linux distributors:
RedHat
www.redhat.com
RedHat software is probably the best known Linux distribution currently available.
MandrakeSoft
www.mandrakesoft.com
Mandrake's Corporate Server offers similar functionality to RedHat, and is much acclaimed for its fast response time with patches and fixes.
SuSe
www.suse.co.uk
A very popular Linux setup in continental Europe, SuSe is now owned by Novell. As such, you can expect great network and server support, particularly for medium/large operations.
