I believe html manpages are built in to most Linux distros' default apache install (or at least easy to set up).
http://localhost/cgi-bin/man/man2html
At least on Ubuntu, after apt-get install apache2, the URL above works.
Back in the day, there was xman: http://www.x.org/archive/X11R7.5/doc/man/man1/xman.1.html
What I'd like is something like this that would also try and gather up stuff from info and /usr/share/doc/PROGRAM/ or whereever it is on the current system and possibly even online docs and try to present them in a reasonably consistent fashion, or at least have it all accessible in one place. But that's a little more ambitious. Also it'd have a terminal program that was a shortcut to remote open a tab in your browser and focus it. The latter would be nice for this.
tengo hambre
Looks pretty -- but the great thing about man is that it runs right there within the terminal. Switching to a GUI browser is a big mode shift and comes with all sorts of distraction. Using a terminal browser like links is probably pretty clunky.