[tetsuo13]

We're using Sandcastle Help File Builder (SHFB) with great success for generating HTML help files.

https://github.com/EWSoftware/SHFB

[loumf]

I also used Sandcastle. We did a major migration to it in about 2010 (from a 3rd party MSHelp generator application -- I'm blanking on the name, which is a good thing, because I would only tell you to stay away from them)