On: Why aren't tabs a window manager feature?

[Adrock]

If you can look past the author's... quirks, I highly recommend the ion wm: http://www.modeemi.fi/~tuomov/ion/

It has great tab support and is highly customizable and scriptable using Lua. Also, once you go with a tiling wm, you'll never go back. It brings the efficiency of you favorite IDEs to the rest of your desktop.