Debian
From DreamHost
Debian Linux
DreamHost's servers run Debian, one of the Linux distributions most commonly used for production servers. Debian is known for its stability and security, as well as for apt-get, an extremely powerful and easy to use package management system. It is noncommercial, and maintained entirely by volunteers.
Debian is also known for its long release schedule. The current "stable" distribution of Debian GNU/Linux is version 5.0, codenamed lenny. It was released on April 11th, 2009. Most Dreamhost servers are running version 4.0 ("etch") or 3.1r4 ("sarge"). New Debian versions are released, in one of the maintainer's words, "when it's ready" and not a day sooner. Luckily, the release procedure is transparent, so that any given time, one can download the upcoming release, which is labeled as "testing". Brand-new, untested packages are also sometimes released in the "sid" distribution, which is labeled as "unstable". The current version is labeled "stable". Despite the labels, one should not assume that anything other than the current "stable" version is actually unstable and therefore unfit for use. There are thousands of people using the not-yet-official versions with little or no problems. Debian's reputation for stability is well-earned.
According to Distrowatch.com, a good site to follow Linux Distributions, there are over a hundred active distributions based on Debian. One of the most popular is Ubuntu by Canonical.
