Lunchbox is a dynamic tiling window manager for X11. It allows windows to be resized by squishing them against the edge of the screen. In a step away from the desktop metaphor, all programs are given a separate workspace and unique arrangement of windows, and any window can become the desktop. It offers an in-built scalable tab replacement called the Title Menu, which allows any window to be swapped with any other window that fits, allowing very fine grained control over the layout of the screen. Finally, although many windows default to tiling, any window can be changed to a Floating mode, which dialog boxes default to.
WindowLab is a small and simple window manager of novel design. It has a click-to-focus but not raise-on-focus policy, a window resizing mechanism that allows one or many edges of a window to be changed in one action, and an innovative menubar that shares the same part of the screen as the taskbar. Window titlebars are prevented from going off the edge of the screen by constraining the mouse pointer. When appropriate, the pointer is also constrained to the taskbar/menubar in order to make target menu items easier to hit.
x9wm is a clone or fork of the 9wm and w9wm X window managers. It is a light alternative for the Mac OS X desktop. All of its source code is contained in a single file. It supports an alterate red colored cursor. It is very light on resources, quite fast, very simple, and easy for long programming, editing, or Web work sessions. You can blend it with Nitrogen and Wbar to create a simple but elegant interface without iconic or stylistic clutter. It does not decorate windows with borders, and it is modal, controlled with the mouse.
Scwm is the Scheme Constraints Window Manager, a highly dynamic and extensible window manager for the X Window System. Scwm embeds Guile Scheme as the configuration and extension language, and includes a sophisticated constraint solver for permitting the user to interactively specify constraints among top-level window sizes and positions. Nearly all decorations can be changed at runtime on a per-window basis. Dynamic loading of C modules is supported. Scwm is self-documenting and provides a powerful protocol for interacting with the window manager from other processes.
GNUSTEP Live CD contains a lot of software for GNUstep, a free implementation of the OPENSTEP framework (which is also directly used in Mac OS X as Cocoa). It includes excellent applications for RAD (GORM and ProjectCenter). The CD is available for i486, AMD64, Apple Mac PowerPC, and Sun UltraSPARC computers.
WMI is a lightweight window manager for X11 which attempts to combine the best features of larswm, ion, evilwm, and ratpoison into one window manager. It supports both the conventional way of managing windows in a overlapping manner and the screen-alike way of managing windows in a non-overlapping fashion.