AfterStep is a continuation of the BowMan window manager which was
originally put together by Bo Yang. BowMan was based on the fvwm window
manager, written by Robert Nation. Fvwm was based on code from twm. And so
on... It is designed to emulate some of the look and feel of the NEXTSTEP
user interface, while adding useful, requested, and neat features. The
changes which comprise AfterStep's personality were originally part of
BowMan development, but due to a desire to move past simple emulation and
into a niche as its own valuable window manager, the current designers
decided to change the project name and move on. BowMan development may
continue, but we will no longer be a part of it.

Major changes from fvwm are:

- NEXTSTEP-like title bar, title buttons, borders and corners. BowMan's
  Wharf is a much worked-out version of GoodStuff.  To avoid copyright
  complications it is not called a "dock." 
- NEXTSTEP style menu. However, the menus are not controlled by
  applications; they are more of pop-up service lists on the root window.
- NEXTSTEP style icons. These styles are hard-coded in the program, which is
  good for the consistent look of the NEXTSTEP interface.

WWW: http://www.afterstep.org/