Mozilla Thunderbird Calendar plugin
From the Mozilla project there are several different calendar solutions available:
- Sunbird calendar application
- Lightning integrated calendar
- Calendar extension
The Calendar extension is not developed any further at the moment because of resource constraints. The Mozilla Sunbird application is (at the name already unveils) a standalone application. The most interesting project for me is the Lightning integrated calendar which is a calendar extension for the Mozilla Thunderbird. On May 14th version 0.1 was released and it integrates into Thunderbird nicely. I am waiting for the future releases which will bring invitations (inactive buttons already available in sunbird), etc. which will definitely be my preferable choice instead of any MS Exchange solutions.
You can read about all the development of lightning at it’s development blog.

