Whats the difference between Sunbird and Lightning?
Sunbird is our standalone calendar application. It doesn’t need another client application to run at the cost of a larger download and higher memory requirements. Because of its standalone nature, Sunbird does not offer any kind of tight integration with an e-mail application, such as Mozilla Thunderbird. Lightning is a calendar extension for Mozilla Thunderbird. It offers calendaring features directly in the Thunderbird User Interface. Further integration features, such as e-mail invites or address book integration are planned for future releases.
