From MEPIS Documentation Wiki
The MEPIS distributions are part of the Debian-family of Linux distributions.
What this means is that, like the Debian distribution itself, MEPIS distributions use the APT system of Linux packaging technologies.
The two distributions that comprise 'MEPIS' are:
1. SimplyMEPIS 2. AntiX
More specifically, SimplyMEPIS and AntiX are based upon Debian's 'stable' repository of software packages.
[Historically, other Debian-family distributions are Knoppix- and Ubuntu-based.]
For details, see:
SimplyMEPIS is based on the 'KDE' desktop environment, one of a handful of various GUI-based graphical windowing systems supported in Linux.
For an overview of SimplyMEPIS, see:
AntiX is based on other 'DE's (desktop-environments).
For an overview of AntiX, see:
Because it is based on 'KDE', SimplyMEPIS is thus more similar to Kubuntu and Aptosid than it is to Ubuntu.
[Ubuntu is Gnome-based, rather than KDE-based. (Gnome is yet another GUI desktop-environment avail in Linux.)] [Aptosid (formerly 'sidux') is also KDE-based, but is based upon Debian's 'unstable' repository.]
[Debian, itself, is 'desktop-environment neutral', and thus can be installed with either 'KDE' or 'Gnome' (or any of a number of other desktop-environments).]
Before you make a decision about actually INSTALLING either SimplyMEPIS or AntiX to your hard-drive, be aware that you can first 'test-drive' these products, by acquiring and booting and running them, from any of their various 'LiveCD' / 'LiveDVD' or 'Live-flash-drive' forms.
Q: You might be asking yourself 'Why MEPIS?', rather than one of the many other Linux distributions.
A: The bottom-line answer is that we believe that the simplicity, ease-of-installation, and very user-friendly support available in our forums, make MEPIS distributions the 'no-brainer' choice!