Classroombookings is a free, open-source and easy-to-use room booking system for schools built using the CodeIgniter PHP application framework. It’s released under the Affero GNU General Public Licence.

Requirements:
- Web server (Apache. mod_rewrite optional)
- PHP 5 (GD optional)
- MySQL 5

Features of Classroombookings:
- Eliminate double-bookings: If a room is already booked by somebody or is used for a timetabled lesson, no one else can book the room for that period. Only administrators and room owners can cancel bookings.
- Unlimited rooms and users: Manage as many rooms and add as many users as you like.
- Easy-to-use: The simplified user interface makes all relative information available at a glance and makes it easy to see which rooms are available to book, and when.
- Custom timetable: Not everybody has a single week timetable with fixed one-hour lessons. This is why we allow administrators to create their own timetable, with their own weekly cycle and lesson times to match the school.
- Cross-platform: No executables, DLLs, runtimes or plugins are required. As it's web-based, a modern web browser is all that's needed for users to book rooms.