snippage from http://wiki.maemo.org/Mer/About
Mer is a new Linux operating system, built upon a thin base of Ubuntu Jaunty combined with the best open-source elements of Nokia's Maemo platform.
The goals of Mer include:
* Improving and developing parts of Maemo that are of interest to the Maemo community.
* Making it easier to port existing desktop applications by hildonizing and adjusting them to the tablet form factor.
* Encouraging third party experimentation and development.
* Supporting tablet hardware no longer receiving updated OS software by Nokia.
* Making Maemo a generic platform for all tablet devices, including non-Nokia ones.
* Focusing Maemo community efforts in platform-related areas