From a wikipedia article:
* WindowSizer - Tiles windows (shareware)
* WinSplit - Tiles windows using keyboard shortcuts (freeware)
* HashTWM - Tiling window manager with automatic tiling (MIT/X11)
* GridMove - Tiles and arranges windows on sophisticated layouts with hotkeys and multi-monitor support (freeware/donationware)
* bug.n - Dynamic, tiling window manager, which tries to clone the functionality of dwm (see list of X window managers) (GPL)
* MaxTo - Tiles windows on user-defined grid by intercepting windows that are maximized or using hotkeys. Supports multi-monitor setups (shareware)
* Twinsplay - Tiles windows using keyboard shortcuts (trial/closed source)