Fluxbox is a lightweight Window Manager for the X Windowing System.
Fluxbox provides configurable window decorations, several predefined and unlimited custom menus, an easy replaceable toolbar and workspaces. The slit can be used to dock small applications, e.g. conky.
For everything else you’ll find help in this wiki.
Fluxbox supports the majority of the Extended Window Manager Hints (EWMH) specification, as well as numerous other Window Hinting standards. This allows all compliant window managers to provide a common interface to standard features used by applications and desktop utilities.