Noticed the initial request for this was posted a year and a half ago, if people have time, might be something worth revisiting, especially with the increase in use of things like iCal on the mac which use RFC2445 (iCalendar) the same as Mozilla Calendar.
Seems the Mozilla Calendar .xpi file doesn't like installing under Debian claiming it can't find libical (but this would appear to be available), suggesting that compile for debian may be the way to go and hence a package..
