PatientOS version 0.21 adds major scheduling functionality. Appointment types can be defined in batches , double or any number of overbooking predefined on the schedule with all appointments defined with a custom color.
Appointments can be rescheduled. Multiple resources viewed by day or week. Custom work schedules, blocking out of schedules.

PatientOS is preparing to go live in December ’07 (scheduling and basic EMR functionality only). To connect to our online demo server in minutes consult this thread http://www.patientos.org/phpBB3/viewtopic.php?
f=3&t=42

For further information, links to downloads, source and more see http://www.patientos.org