The web page edition (for the same version - 0.7.2 - that you referenced above) does still exist, on the googlecode site. Link here -->
http://web.sigil.googlecode.com/git/...roduction.html
It has not yet been updated AFAIK, but given all the improvements the guys are making at the moment, any new version probably wouldn't be much more obsolete than this one within a short period of time.