I agree with Jamie's suggestion of Seamonkey, since just about everything else assumes some fancy underlying technology (i.e. is oriented towards a specific server etc.).
However /if/ you can get it for your preferred platform Kompozer is based on the same Mozilla/Netscape codebase, and is somewhat more advanced. I think that a Windows binary should still work, Linux (Debian etc.) binaries don't but a few days ago I managed (with a fair amount of hackery) to build it to run on a current x86-64 Debian.
MarkMLl