Multiple large virtual desktop window manager - Version 3
Fvwm is a virtual window manager for the X windows system. It was originally a feeble fork of TWM by Robert Nation in 1993 (fvwm history), and has evolved into the fantastic, fabulous, famous, flexible, and so on, window manager we have today.
Fvwm is a ICCCM/EWMH compliant and highly configurable floating window manager built primarily using Xlib. Fvwm is configured using a configuration file, which is used to configure most aspects of the window manager including window looks, key bindings, menus, window behavior, additional modules, and more. There is a default configuration file that can be used as a starting point for writing one's own configuration file.
Fvwm is a light weight window manager and can be configured to be anything from a small sleek window manager to a full featured desktop environment. To get the most out of fvwm, one should be willing to read the documents, and take the time to write a custom configuration file that suites their needs. The manual pages and the fvwm wiki can be used to help learn how to configure fvwm.