Mozilla Lightning is a desktop calendar application that is distributed as an extension to Mozilla Thunderbird. Lightning is built as a Thunderbird extension because its goal is tight integration between your e-mail client and your calendar.
Lightning builds upon the similar Mozilla Sunbird application by adding a number of features found in other office productivity platforms [...]

Rainlendar is a cross-platform calendar program that sits on your desktop instead of in a window. Like most other calendar applications, Rainlendar supports the iCal format so that it can read calendars saved with other programs, like Google Calendar and Apple iCal. Rainlendar’s localization features allow you to operate in your own language.
Rainlendar has both [...]

Google Calendar is a full-featured, web-based calendar with a variety of sharing features. Like Google Search, Google Calendar does an excellent job of understanding your input. So what exactly does that mean? Let’s say you want to schedule an appointment with Mary at 10am. Instead of putting the event name in a text box and [...]

Spanning Sync keeps your Google Calendar and your Mac’s iCalendar up to date with each other, eliminating the need for you to manage separate calendars. After you’ve set up Spanning Sync, changes made to Google Calendar will show up in iCal, and changes made in iCal will appear in Google Calendar.
Additional features of Spanning Sync [...]

iConcertCal is a plug-in for iTunes that uses the artists in your library to load up a calendar of concerts that might interest you. iConcertCal goes out, downloads all the concert listings, and offers them up on a calendar, right inside iTunes. It doesn’t get any simpler than that, nor any more useful!
If you [...]

GCALDaemon is a software package intended to keep your offline and online applications in sync with each other. That means if you use desktop applications like iCalendar, and also web-based applications like Google Calendar, GCALDaemon can keep them in sync and stop you from doing twice as much work to keep both systems up to [...]