FVWM was forked from twm in 1993 by Robert Nation to add virtual desktop support while drastically reducing memory usage. It spawned an entire family of window managers including AfterStep, FVWM95, and Window Maker.
FVWM was derived from twm source code with the addition of virtual desktop support, a pager module, and dramatically reduced memory footprint. It introduced a modular architecture where external helper programs (modules) communicated with the window manager via pipes, enabling extensibility without bloating the core.
In 1993, Robert Nation, a software engineer at Sanders (later Lockheed Martin) working on acoustic signatures for the U.S. Department of Defense, needed a window manager that could run efficiently on his resource-constrained hardware -- a 33 MHz 486 laptop with only 4 MB of RAM running Linux and X11 for analyzing large spectrograms. He forked twm (Tab Window Manager), the standard X11 window manager, to add virtual desktop support while reducing memory consumption.
The first version, FVWM 0.5, was released on June 1, 1993, bundled with the Rxvt terminal emulator. The name originally stood for 'Feeble Virtual Window Manager,' reflecting the minimal feature set of early releases, though Nation later claimed the F had no official meaning. By fall 1993, FVWM became an independent package with the 1.0 release. In 1994, Nation stopped developing FVWM and passed maintainership to Charles Hines.
FVWM became one of the most influential window managers in Unix history, spawning numerous derivatives. AfterStep (1996) emulated NeXTSTEP aesthetics using FVWM's modular framework. FVWM95 (1996) mimicked the Windows 95 interface. Window Maker (1997) was created by AfterStep contributor Alfredo Kojima as a clean-room rewrite for GNUstep. The project continues today as FVWM3.
FVWM 0.5 released, bundled with Rxvt
FVWM 1.0 released as independent package
Nation passes maintainership to Charles Hines
AfterStep and FVWM95 fork from FVWM
Window Maker created by ex-AfterStep developers
FVWM became the most forked window manager in Unix history, spawning AfterStep, FVWM95, Window Maker, and others. It established the modular window manager architecture that influenced later projects and demonstrated that the Unix desktop could be highly customizable. FVWM was the default window manager for many early Linux distributions.