Anarchy is a window manager for the X Window System. It is implemented in less than 500 lines of CLOS oriented Scheme code. The implementation language is Gauche Scheme. Despite its small code size, it supports most functions expected of a basic window manager (move, resize, hide, minimize, maximize, list windows, root menu).
Athene is a desktop system for Linux that uses its own graphics drivers for high speed access to your graphics card. Because the Athene desktop and its applications have direct access to the graphics hardware, they have a significant speed advantage over conventional X applications. Athene is also backwards compatible with your existing X11 software. It features a highly responsive interface, scalable icons, translucency, alpha blending, Unicode support, and Windows compatibility.
Blackbox is yet another addition to the list of window managers for X. It is written in C++, sharing no common code with any other window manager (even though the graphics implementation is similar to that of WindowMaker). It features small code size, a fast interface with simple menus, multiple workspaces, decorated windows, built-in graphics code to render solids, gradients, and bevels on the fly, and more.
Bluetile is a tiling window manager 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.
CTWM is a highly-configurable window manager based on the classic TWM window manager. It supports xpms, multiple workspaces, advanced icon managment, animated icons and backgrounds, 3D titles and borders, etc. It offers rudimentary Gnome support and is backwards-compatible with TWM.