GRR

GRR is an open-source resource booking system for managing shared resources such as rooms, equipment, vehicles and personnel. It provides a centralised calendar to coordinate availability and reduce booking conflicts, with configurable rules for hours, access and notifications.

Features include access control, periodic reservations, holiday days, pending reservations to confirm by a set date, moderation workflows requiring manager approval, booking on behalf of others or external people, custom fields per domain, cycle days, automated email notification settings, delegated administration, temporary resource unavailability, resource presentation pages with images, multiple planning views, customizable booking hours, per-user quotas, participant management, and bulk booking or release. It is built in PHP with a responsive design for use across devices, and includes real-time usage tracking and detailed reports.

GRR is available as a free self-hosted open-source edition that you install and maintain on your own server, with no user or resource limits and SSO, LDAP and IMAP connections. A paid cloud edition, MyGRR, includes hosting, daily backups, updates handled by support, support, an ICS module, and SSO connections with Microsoft 365 and Okta, also with unlimited users and resources.