This is not a list of every window manager ever created -- there are way too many. This is a list of other interesting WMs that you may like better than Parti, or that may serve as useful sources of ideas:

  • Ion: One of the greats -- the first tiling WM, as far as I know. Current version is non-free.
  • wmii: One of the greats -- tags instead of workspaces, automatic columnar layout, tiling vs. floating layers, etc.
  • dwm: wmii, but even more minimalist.
  • tritium: The other tiling WM in Python. Based on plwm and python-xlib, rather than pygtk and libx.so, so hard to share code directly. Aims to clone Ion.
  • PLWM: A window manager (library) in Python, using python-xlib.
  • PyWM: A window manager in Python, built by wrapping FLWM/FLTK in Python.
  • Awesome: Tiling WM based on dwm.
  • Emacs: Okay, not normally an X11 WM, but it's a system for arranging and switching between rectangular workareas, with some very sophisticated mechanisms. See ido's buffer-switching interface, for instance.
    • XWEM: Makes emacs actually an X11 WM. Very interesting design, because it follows the Emacs view of the world (frames, buffers, minibuffer, keymaps, hooks, etc.) instead of the traditional WM way of doing things.
  • Firefox: Also not normally an X11 WM, but with the addition of tabbing, browsers have become very similar indeed. Many extensions have interesting interfaces to these tabs -- putting more information into the tab itself, changing how one moves between tabs, etc.
    • Pyro: Makes Firefox, yes, an actual X11 WM. Very interesting design, because it follows the Firefox/HTML view of the world (box-model, CSS, javascript, etc.) instead of the traditional WM way of doing things. (Also, one of maybe 4 codebases that really deals with the quirks of XComposite.)

Other interesting software in this space:

  • SuperSwitcher: Fancy window management key bindings, mostly aimed at Gnome -- window switching, maximize/minimize, desktop switching, etc.
  • Deskbar
  • KRunner
  • Quicksilver: For OS X (but FOSS).
  • Enso: Closed source, but partly by Jef Raskin...