From Extrovert Software:
Thyme is a robust, Web-based calendar suite. It can be used as a personal planner, a company or organization's event calendar, an RSS gateway, an iCalendar service, an application embedded into your PHP enabled Web site or intranet. It supports multiple calendars, multiple users and groups, timezone compensation, iCalendar standards, RSS syndication, themes, multiple languages, Joomla integration, phpBB2, PHPNuke, generic sql, Mambo/Joomla and LDAP authentication, e-mail reminders, e-mail notifications, e-mail subscriptions, remote updates via Sunbird and Apple iCal (among other programs that support iCalendar), event request/approval system, advanced repeating rules, file attachments, color coding of categories, multiple views. See our website for a complete list of features. Try one of our online demos and download a free 30 day trial.