Lightning is a free, cross-platform extension for the Mozilla Thunderbird email client. This is not a stand-alone program, it adds a calendar tool to Thunderbird, which must also be installed on your computer.

• Software Requirement: You must have the Mozilla Thunderbird client installed on your computer
• Computer/Processor: Intel x86 or PowerPC G3, G4, or G5
• Operating System: Mac OS X 10.2.x and above
• Memory: 128 MB RAM (256 MB RAM or greater recommended)
• Disk Space: 200 MB

Mozilla Lightning is available at no cost through the Mozilla Sunbird Web site.