[ Thanks to Adam
Williamson for this link. ]
“Well, this time we really mean it: Firefox 2 is dead,
long live Firefox 3! Firefox 2 has now been entirely removed from
the distribution, and from Beta 2 onwards, Firefox 3 is the
supplied version. In addition, we are now using xulrunner, the
implementation of the Gecko layout engine (used by Firefox and
other browsers) as a separate library rather than integrated into
Firefox. This eases maintenance of both Firefox and the various
other packages which use the Gecko engine, and will ensure that in
future we do not have to issue updates to every Gecko-based
application every time an update for Firefox or xulrunner is
required.”