The Feynman Lectures on Physics, Volume I
I was the project lead on this, which involved converting the <i>Feynman Lectures</i> from LaTeX to HTML. I'd be happy to answer any questions.<p><i>Update</i>: Most of the questions center on cost. I've answered in more detail below, but the short version is simple: no off-the-shelf converter was remotely sufficient for our needs, so we had to write lots of custom software, and writing custom software is hard.