- 1 Desktop Environment
- 1.1 OpenWindows
- 1.2 Common Desktop Environment
- 1.3 GNOME
- 1.4 KDE
- 1.5 Enlightenment
- 1.6 Xfce
- 1.7 LXDE / LXQt
- 1.8 ROX
- 1.9 Sugar
- 1.10 notanos
- 1.11 EDE
- 1.12 Pantheon
- 1.13 Budgie Desktop
- 1.14 OS.js
- 1.15 Lumina
- 1.16 XDE
- 1.17 dedaemon
- 1.18 NEXTSPACE
- 1.19 Looking Glass
DEs are generally tightly integrated. A full DE install is required for systematic control of userspace applications.
1989-2000, Sun Microsystems
Common Desktop Environment
- Glade - a RAD tool to enable quick & easy development of user interfaces for the GTK+ toolkit and the GNOME desktop environment. The user interfaces designed in Glade are saved as XML, and by using the GtkBuilder GTK+ object these can be loaded by applications dynamically as needed. By using GtkBuilder, Glade XML files can be used in numerous programming languages including C, C++, C#, Vala, Java, Perl, Python,and others.
- shellshape - a gnome-shell (Gnome 3) extension that adds smart and user-friendly tiling window features to your gnome desktop, inspired by bluetile.
- https://wiki.archlinux.org/index.php/Consort - fork of gnome classic
- MATE Desktop Environment - the continuation of GNOME 2. It provides an intuitive and attractive desktop environment using traditional metaphors for Linux and other Unix-like operating systems. MATE is under active development to add support for new technologies while preserving a traditional desktop experience. See the Roadmap The MATE Manifesto outlines some of the principles that guide the project.
- http://cinnamon.linuxmint.com/ - fork of Gnome Shell, now a DE in it's own right
- http://plasma-active.org/ - kde related for tablet
- Trinity Desktop Environment - a computer desktop environment for Unix-like operating systems with a primary goal of retaining the function and form of traditional desktop computers.
- Enlightenment is not just a window manager for Linux/X11 and others, but also a whole suite of libraries to help you create beautiful user interfaces with much less work than doing it the old fashioned way and fighting with traditional toolkits, not to mention a traditional window manager. It covers uses from small mobile devices like phones all the way to powerful multi-core desktops (which are the primary development environment).
- Xfce Desktop Environment - a lightweight desktop environment for UNIX-like operating systems. It aims to be fast and low on system resources, while still being visually appealing and user friendly.
LXDE / LXQt
- http://lxde.org - Openbox WM
- ROX is a fast, user friendly desktop which makes extensive use of drag-and-drop. The interface revolves around the file manager, or filer, following the traditional Unix view that `everything is a file' rather than trying to hide the filesystem beneath start menus, wizards, or druids. The aim is to make a system that is well designed and clearly presented. The ROX style favours using several small programs together instead of creating all-in-one mega-applications.
- Sugar Labs - a learning platform that reinvents how computers are used for education. Collaboration, reflection, and discovery are integrated directly into the user interface. Sugar promotes "studio thinking" and "reflective practice". Through Sugar's clarity of design, children and teachers have the opportunity to use computers on their own terms. Students can reshape, reinvent, and reapply both software and content into powerful learning activities. Sugar's focus on sharing, criticism, and exploration is grounded in the culture of free software (FLOSS).
- EDE - small desktop environment built to be responsive, light in resource usage and to have familiar look and feel. It runs on Linux, *BSD, Solaris, Minix, Zaurus and even on XBox.
- https://github.com/edeproject - dead?
- https://wiki.archlinux.org/index.php/Pantheon - elementaryOS
- Budgie - a desktop environment originally started in 2013. It aims to provide a familiar, modern and functional experience whilst getting out of the user’s way. Since its inception, the project has seen many enhancements and evolutions, as we continuously enhance the experience to better suit the growing needs of our users.
- Lumina Desktop Environment - A Lightweight, Customizable, and Seamless Desktop Experience. For BSD and Linux Operating Systems 
Modular DE for non-DE window managers?
- https://github.com/mortie/dedaemon - Desktop Environment-like functionality in a daemon.
- https://github.com/trunkmaster/nextspace - desktop environment that brings NeXTSTEP look and feel to Linux. I try to keep the user experience as close as possible to the original NeXT's OS. It is developed according to "OpenStep User Interface Guidelines".  
- https://en.wikipedia.org/wiki/Project_Looking_Glass - a now inactive free software project under the GPL to create an innovative 3D desktop environment for Linux, Solaris, and Windows. It was sponsored by Sun Microsystems.Looking Glass is programmed in the Java language using the Java 3D system to remain platform independent. Despite the use of graphics acceleration features, the desktop explores the use of 3D windowing capabilities for both existing application programs and ones specifically designed for Looking Glass.