|User since||Aug. 25, 2007|
|Number of add-ons developed||0 add-ons|
|Average rating of developer's add-ons||Not yet rated|
There _is_ 64-bit support Rated 5 out of 5 stars
Though this site does not provide a link to it, there is actually a 64-bit version. You can find it here: http://releases.mozilla.org/pub/mozilla.org/calendar/lightning/releases/0.5/contrib/linux-x86-64/
See the plugin homepage for other platforms.