Lightning brings the Sunbird calendar to the popular email client, Mozilla Thunderbird. Since it's an extension, Lightning is tightly integrated with Thunderbird, allowing it to easily perform email-related calendaring tasks.
Lightning is licensed under the MPL/GPL/LGPL triple license, allowing use of the files under the terms of any one of the Mozilla Public License, the GNU General Public License, or the GNU Lesser General Public License.
You can find builds for the different platforms on our download page. All localizations are included in the single .xpi file for ease of installation.
Please refer to the Calendar:WCAP Guide for further information about the enhancements.