A window-matching utility, inspired by Sawfish's "Matched Windows" option and
the lack of the functionality in Metacity. Metacity lacking window matching is
not a bad thing -- Metacity is a lean window manager, and window matching does
not have to be a window manager task.

Devil's Pie can be configured to detect windows as they are created, and match
the window to a set of rules. If the window matches the rules, it can perform a
series of actions on that window. For example, I make all windows created by
X-Chat appear on all workspaces, and the main Gkrellm1 window does not appear
in the pager or task list.