The goal here is to update and amplify the long-existing LaTeX(2e) reference manual, which has been included in free TeX distributions for many years. It originated with George Greenwade, was updated for LaTeX 2.09 by Stephen Gilmore, and for LaTeX2e by Torsten Martinsen. None of these folks can continue work on the project, so I (Karl Berry) decided to restart it, initiating what I very much hope will be a collaborative effort.
The goal is not to replace the major books about LaTeX; that would not be realistic. What is feasible, I hope, is to summarize the features (commands, environments, options, etc.) of core LaTeX2e. This information is reasonably available from the free LaTeX sources and documentation, but is not so easy to access from there.
The manual is currently written in Texinfo. I like Texinfo, and want to keep it available in that form. However, I'm more than happy to accept new material in plain text, LaTeX, Docbook, or whatever.