iZeit is a calendar written in PHP. It can use either MySQL, PostgreSQL, Microsoft SQL or a text file to store data, so iZeit runs on nearly all server configurations.

Features of iZeit:
- Categories for different events.
- To-do list with categories.
- Multiple users with their own login, password and customisable settings.
- Easy integration with other pages.
- Popup information shown when you mouse over an event.
- Customisable views and filters, to show items occurring on the same day, week, month or year.
- Users can comment on events.
- Public and private events.
- Support for recurring events.
- Import & Export to the iCal format.
- No database needed!
- MySQL, PostgreSQL and Microsoft SQL support.
- Translations into Dutch, Turkish, Simplified Chinese, Czech, Portuguese, Spanish, Italian, Danish, German, Swedish, Russian, Greek, French and Polish.
- Simple, user friendly control panel to make customization and management easy.
- RSS feed to keep track of events.
- PDF output to enable easy sharing and printing of events.
- Mobile XHTML support for PDAs and Smartphones.
- ... and much more