Lightning brings Sunbird together with our popular email client, Mozilla Thunderbird.
Much more polished user interface in the calendar views
Event invitations can be sent and received via iMIP/iTIP (Lightning only)
Working hours are back
Automatic migration of data in Sunbird 0.2, iCal.app, and Evolution
Much improved printing functionality
Better integration of Lightning into Mozilla Thunderbird (Printing, Undo/redo,
Support for Google Calendar (via the Google Calendar Provider extension)
and much more. A full list of changes that have gone into this release can be
found on The Rumbling Edge weblog.
Tools and Utilities
Product page: here