subtle is a grid-based manual tiling window manager with a strong focus on easy but customizable look and feel. In comparison to other tiling window managers, subtle has no automatic tiling of the screen size in any way. Instead, windows are arranged according to positions inside of a grid. These positions are called gravities.
QuickTile is a simple attempt to duplicate the basic functionality of WinSplit Revolution for users who don't like the Compiz Grid plugin. It should work on any X11 desktop with PyGTK 2.2+, a window manager that supports the modern range of NETWM hints, and (if you want internal keybinding) python-xlib.
Notion is a tiling tabbed window manager for X. This means the screen can be freely divided into tiles that contain the client windows. Multiple client windows can occupy the same tile; in that case they will be tabbed, much like browser tabs. This way, windows will not overlap and it becomes easier to manage your screen real estate. Its functionality can be configured and even extended with Lua scripts. Various scripts are available, such as for NetWM features and multihead support.