I loved Ion (http://tuomov.iki.fi/software/) to death back in the day and for a few years was floating in limbo after it's author went weird about it's licensing.
I'm pleased to say that there is now Notion (not ion):
Notion is a fork of an earlier version of Ion with a more permissible license but behaves and looks exactly like Ion always did.
Notion and Ion were so-called stacked tiling window managers, their position and layout were not fixed in patterns of dividing the screen up like (iirc) Awesome and XMonad.
Same story here, regarding Ion. A guy I know who also used Ion said that's enough, we can't find a replacement so let's write one. I helped a bit. It does what we need, it's fast, and it's easy to configure. https://opensource.conformal.com/wiki/spectrwm
I'm pleased to say that there is now Notion (not ion):
http://notion.sourceforge.net/
Notion is a fork of an earlier version of Ion with a more permissible license but behaves and looks exactly like Ion always did.
Notion and Ion were so-called stacked tiling window managers, their position and layout were not fixed in patterns of dividing the screen up like (iirc) Awesome and XMonad.