howm: Write fragmentarily and read collectively.

Howm is a note-taking tool on Emacs.  It is similar to emacs-wiki;
you can enjoy hyperlinks and full-text search easily. It is not
similar to emacs-wiki; it can be combined with any format.

WWW: http://www.me.ics.saitama-u.ac.jp/~hira/emacs/howm/index.html