Enlightenment!

Cinnamon is a Linux desktop which provides advanced innovative features and a traditional user experience. The desktop layout is similar to GNOME 2. The underlying technology is forked from GNOME Shell. The emphasis is put on making users feel at home and providing them with an easy to use and comfortable desktop experience.

The "Lightweight X11 Desktop Environment" is an extremely fast-performing and energy-saving desktop environment. Maintained by an international community of developers, it comes with a beautiful interface, multi-language support, standard keyboard short cuts and additional features like tabbed file browsing. LXDE uses less CPU and less RAM than other environments. It is especially designed for cloud computers with low hardware specifications, such as, netbooks, mobile devices (e.g. MIDs) or older computers. LXDE can be installed with distributions like Ubuntu or Debian. It provides a fast desktop experience; connecting easily with applications in the cloud. LXDE supports a wealth of programs that can be installed locally with Linux systems. The source code of LXDE is licensed partly under the terms of the the General Public License and partly under the LGPL. »

LXQt is the Qt port and the upcoming version of LXDE, the Lightweight Desktop Environment. It is the product of the merge between the LXDE-Qt and the Razor-qt projects: A lightweight, modular, blazing-fast and user-friendly desktop environment.

Lumina is a lightweight, BSD licensed, standards-compliant desktop environment based upon Qt and Fluxbox. It is being developed on PC-BSD, and is being packaged for distribution on the PC-BSD package repository as well

Cairo Shell is a replacement shell for the Microsoft Windows operating systems. Like other shell alternatives, it replaces the default Windows Shell. Cairo Shell will be free to download and use when it is released.

Elokab Desktop Environment is an open-source independent desktop environment for Linux which uses QT libraries like KDE .

Bluetile is a tiling window manager for Linux, designed to integrate with the GNOME desktop environment. It provides both a traditional, stacking layout mode as well as tiling layouts where windows are arranged to use the entire screen without overlapping. Bluetile tries to make the tiling paradigm easily accessible to users coming from traditional window managers by drawing on known conventions and providing both mouse and keyboard access for all features.

Fork of Enlightenment version 17 (commonly called E17) used as the main desktop environment on Bodhi Linux