Before using sawfish I tried nearly every window manager, always missing some killer-feature :-)

Fluxbox was my favourite, with its implementation of pwm-like tabs and extended shortcuts. Unfortunately the theme engine was not smart enough to enable me to do what I want (one thing I really like is to have border-only or even borderless windows). So I switched to sawfish and had to implement the whole tabs thing.

In my opinion, beautiful and usefull tabs are like this:

Some people prefer using a split title bar. A modified version by Scott Driven can be found on his sawfish webpage

To use tabs in sawfish you will need some .jl files available in the Sawfish page : tab.jl, group.jl,marks.jl and a tab-enabled theme like this one