Sawfish (the window manager formerly known as Sawmill) is an extensible window manager using a Lisp-based extension language. All window decorations are configurable and all user-interface policy is controlled through the language. Its aim is to manage windows in the most flexible and attractive manner possible. As such it does not implement desktop backgrounds, application docks, or other things that may be achieved through separate applications. Sawfish is mostly GNOME-compliant; almost all configuration may be made through a graphical interface.
ZWM is an SDL-based window manager and widget library intended to be used in cross-platform applications. It features basic widgets like buttons, lists, containers, a file browser, combo-box, and many more. It also features support for mutimedia playback (MPEG, MP3, WAV, MIDI, Ogg, etc.).
Felidae is a collection of modules for Fvwm. FvwmStorage lets you define variables, load and store them from/to files, and execute any fvwm command using them. It is especially useful to interactively change the fvwm configuration. FvwmWallpaper lets you change your X wallpaper from within Fvwm. It tries to find the best way to display your picture and resizes it if necessary. FvwmXMMS lets you control XMMS by sending commands to this module. FvwmOsd lets you display an on-screen display on your X display. FvwmOsd is organized in different "channels", each of which you can configure and use independently of the others.