ive been working on one for a while, 'element' on gitorious/rubyforge/repo.or.cz
1461 lines of ruby if sloccount is accurate. includesa full Filesystem-backed key/value/triple-store with range query and web-arch complaint API. using it as a mail app as well, screenshot: http://i574.photobucket.com/albums/ss187/ix9/hyper/2010-03-27-051943_1280x800_scrot.png
