'Hedwig' is an observing proposal handling system developed by the East Asian Observatory for use at the JCMT. It has been used successfully for the last 5 years. The system is open source and designed to be easy to customize for use at other telescopes. For flexibility, semesters, submission queues and calls for proposals are all defined via the web interface. Time-consuming tasks (e.g. processing uploads and looking up publication references) are performed in the background to keep the web interface running smoothly even during busy times.
The system includes a number of integrated tools to assist with proposal preparation and review. These include integration time calculators for SCUBA-2 and JCMT's heterodyne instruments, a 'clash' tool to compare target positions to large programs or archival data, and a target availability tool to check that objects are suitable for a given semester.
It is loosely integrated with the JCMT's Observation Management Project (OMP). Project definitions are automatically created for accepted proposals and Hedwig provides an OAuth2 service to allow users to log in with a single account. The sky coverage of archival data is fed back to the proposal system in MOC format.