I was looking for that a while back, too, and a Wikipedia search led me to BlueGriffon (http://bluegriffon.org/ http://bluegriffon.org/), which (through various

I was looking for that a while back, too, and a Wikipedia search led me to BlueGriffon (http://bluegriffon.org/ http://bluegriffon.org/), which (through various forks like Nvu etc.) was apparently originally based on the "Composer" part of Netscape / Mozilla.