PHP iCalendar is a php-based iCal file parser. Its based on v2.0 of the IETF spec. It displays iCal files in a nice logical, clean manner with day, week, month, and year navigation, printer view, RSS-enabled, and searchable. It supports 12 languages, is fully theme-able, and has complete timezone support.
We are using this on the Lewis Elementary site to share our school calendar. Our school secretary is using the calendar tool in Mozilla to keep track of school events. The iCal file that is created is published to the calendar directory on the server and the pages are created by PHP iCalendar. It also creates RSS files in daily, weekly and monthly format. Using the weekly RSS feed, we are also able to automatically post events for the current week on the main web page.