WebCalendar is a PHP-based calendar application that can be configured as a single-user calendar, a multi-user calendar for groups of users, or as an event calendar viewable by visitors. It then can later be included in other PHP-based applications.

WebCalendar can be setup in a variety of ways, such as:
- A schedule management system for a single person
- A schedule management system for a group of people, allowing one or more assistants to manage the calendar of another user
- An events schedule that anyone can view, allowing visitors to submit new events
- A calendar server that can be viewed with iCal-compliant calendar applications like Mozilla Sunbird,
- Apple iCal or GNOME Evolution or RSS-enabled applications like Firefox, Thunderbird, RSSOwl, or FeedDemon, or BlogExpress.

Features of WebCalendar:
- XHTML/CSS compliance
- Multi-user support
- 30 supported languages: Basque, Bulgarian, Chinese-Big5, Chinese-GB2312, Czech, Danish, Dutch, English-US, Estonian, Finnish, French, Galician, German, Greek, Holo-Big5, Hungarian, Icelandic, Italian, Japanese, Korean, Norwegian, Polish, Portuguese_BR, Portuguese, Romanian, Russian, Spanish, Swedish, Turkish, Welsh
- Auto-detect user's language preference from browser settings
- View calendars by day, week, month or year
- View another user's calendar
- View one or more users' calendar via layers on top of your own calendar
- Add/Edit/Delete users
- Add/Edit/Delete events
- Repeating events including support for overriding or deleting (exceptions)
- Configurable custom event fields
- User-configurable preferences for colors, 12/24 time format, Sun/Mon week start
- Online help
- Checks for scheduling conflicts
- Email reminders for upcoming events
- Email notifications for new/updated/deleted events
- Export events to iCal, vCal or Palm
- Import from iCal, vCal or Palm
- Optional general access (no login required) to allow calendar to be viewed by people without a login (useful for event calendars)
- Users can make their calendar available publicly to anyone with an iCal-compliant calendar program (such as Apple's iCal, Mozilla Calendar or Sunbird)
- Publishing of free/busy schedules (part of the iCal standard)
- RSS support that puts a user's calendar into RSS (WebCalendar 1.1 )
- User authentication: Web-based, HTTP, LDAP or NIS

What's New in This Version:
- Fixed for "undefined function require_valide" bug.
- Other minor bug fixes.
- Updated Greek translation