Scientific Linux – The Big Physics Community Linux of Choice
To reduce redundancy and provide commonality, Fermilab and CERN have anointed a version of Linux as Scientific Linux.
The FAQ on the site talks about the foundation of Scientific Linux as the “Enterprise version” of Linux. I believe it’s based on a version of Red Hat Linux but the FAQ declines to mention it citing trademark restrictions.
As always the issue of support comes up since the community provides it rather than a particular vendor. Fermi Lab offered a Fermi Linux so the support users found with that version will probably be what they find with the Scientific Linux version.
A general history of Scientific Linux can be found here.