ion3 is/was a tiling WM that would primarily be operated with the keyboard, but also allowed for basic operations, like switching and dragging windows as well as resizing frames, using a mouse.
The windows are tiled in frames, with their titles in tabs above the actual content, so multiple windows could be inside one frame, but only one remains visible with its tab highlighted accordingly. Clicking the mouse on a tab is an alternative way of switching the active window. Secondary mouse button on the tab would bring up a menu with basic window operations.
It's configuration files are written in lua code, thus enabling rather dynamic setups.
ion3 also has a very basic floating window mode that could optionally be chosen when creating new workspaces (virtual desktops). Windows can not be iconified, but at least rolled up.
A minor flaw in ion3 is not being able to use the mouse to bring up a root menu for launching applications. So it could be operated with the mouse to some degree, but relies on the keyboard or at least some sort of launcher to start applications. Switching workspaces is also not possible without the use of a keyboard or a workaround that would translate mouse events to keys.