TeamCal Pro

TeamCal Pro is a web application supporting project teams in scheduling their members' presence/absence. With TCP you can easily see who's in and who's not and why - and all that in an attractive optical interface. TCP is powered by PHP and MySql. It supports user authentication, user self-registration, user groups, avatars, absence icons, absence counts, allowances and much more. It comes highly recommended by the users who have suggested many improvements that have been built in. There is also a light version available working with flat INI files.