Mepis GNU/Linux
Mepis is a Debian-based GNU/Linux distribution founded about two years ago. As with some others, it comes in several versions. There's SimplyMEPIS, MEPISLite, SoHoServer, and Desktop OnTheGo.
SimplyMEPIS is the general desktop distribution and tries to balance stability with being up-to-date. The latest version, 3.4-3, released last month, includes the 2.6.15 kernel, KDE 3.4.3, OpenOffice 2.01, Firefox 1.5, and 900 or so other packages. You Debian gurus out there could probably guess that Mepis is built on the Debian testing (Etch) pool. This is so you can get relatively stable packages but also the more current versions. Conversely, if they had used the stable pool (Sarge) of Debian, you would very quickly end up with very dated programs. This is not a GoodThing when it comes to security updates. It is less a problem with regular program updates but if you want to have a secure, leading edge distribution, Debian stable may not be the way to go. So, to me, it is well that they went with Etch.
MEPISLite is targeted at people running Windows98 PCs. That is, relatively old computers with limited capabilities. Hence, the Lite version of Mepis is supposed to be less taxing on such hardware. One of the differences is that KOffice is used, rather than OpenOffice and Konquerer rather than Firefox. Otherwise, it is very similar to SimplyMEPIS.
SoHoServer is designed for the small business that needs to have server that is easy to setup and administer. As such, stability is more important that being leading edge. That is, you don't want your server going down because the latest version of some package has a bug. Hence, this distribution is based on the Debian stable pool (Sarge, mentioned earlier). It includes pre-configured server software such as "Apache2, PHP4, Perl, Mysql, Proftpd, Bind, DHCPd, Postfix, Dovecot, Shorewall, Squid, DansGuardian (love that name-ed.), Webmin, and Usermin." With a minimal background in *nix, you should be able to install and have running a server for your business. That said, it probably takes years to master the details needed to securely run a Internet facing server. So, it would be wise to get yourself some training or at least a book or two before you try this. YMMV. Use at your own risk.
Desktop OnTheGo is a "USB-key"-based technology that apparently shrinks things down to fit a desktop that you can take with you. I don't have much information on how this works and haven't tried it myself. I'm not even sure what they are referring to when they talk about a USB-key. Maybe they are talking about USB flash drives. I dunno. But if you have a need to take your desktop with you, without carrying a laptop, you may want to check into this. As for me, I'm thinking I may try it to see if this can connect to our Netware network. We shall see.
In any case, there are many distributions based on Debian. This popularity, perhaps, reflects the ease of use of Debian. Which distribution is best for you, only you can determine. But so far, Mepis looks like a pretty good one to me.
Aloha!