ZDNet have tested Mandriva Linux 2006, Novell Linux Desktop 9, Red Hat Desktop 4, SUSE Linux 10 and Ubuntu Linux 5.10 for small business. Long store short: Ubuntu wins.
Read it yourself.
And the winner is
We emerged from our Linux experience with a strong preference for Ubuntu Linux 5.1, with SUSE Linux 10 a close second. Both did everything we required of them, and both have very low setup costs. Ubuntu, in particular, costs absolutely nothing to purchase.
When choosing an operating system for your business, local support may be crucial. For instance, there may be Windows applications that need to be ported, or run in a Windows emulator on Linux. In which case you may need an integrator with experience in your particular line of business.
If you prefer to deal with a consultancy-like support service, then Novell Linux Desktop 9, may be a good move, while the very corporate Red Hat Desktop 4, could prove a sensible option for companies with large numbers of desktops.
Our Editor's Choice for the small business, however, is the solid, well integrated and free Ubuntu Linux 5.1.