dwm is a fast and simple window manager for X11. It manages windows in tiled and floating layouts. Either layout can be applied dynamically, optimizing the environment for the application in use and the task performed. Windows can be tagged with one or multiple tags. Selecting certain tags displays all windows that are accordingly tagged. dwm is the little brother of wmii.
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.
awesome is a highly configurable, next generation framework window manager for X. It is very fast, light, and extensible. It is primarily targeted at the power user, developer, and anyone dealing with everyday computing tasks who wants to have fine-grained control over a graphical environment.
Notion is a tiling tabbed window manager for X. This means the screen can be freely divided into tiles that contain the client windows. Multiple client windows can occupy the same tile; in that case they will be tabbed, much like browser tabs. This way, windows will not overlap and it becomes easier to manage your screen real estate. Its functionality can be configured and even extended with Lua scripts. Various scripts are available, such as for NetWM features and multihead support.
DSWM (Deep Space Window Manager) is a tiling keyboard-driven X11 window manager. It is based on StumpWM code and is written entirely in Common Lisp and oriented for good usability with minimum startup configuration and good integration with Emacs. The project is under hard development, so it has many experimental features.
echinus is a lightweight window manager for X based on dwm's source code. It manages windows in tiled, maximized, and floating layouts. It is extremely small, rather fast, and supports Xft. It features nice titlebars, multiple desktops, theming support, a simple configuration file, the ability to switch desktops with the mouse wheel, X bitmaps for title buttons, and true transparency support (through xcompmgr). There is no need to recompile or restart X to change its configuration.