Tamanu is a free and open-source patient-level electronic medical record system for desktop and mobile. Designed specifically low-resource and remote settings, Tamanu is open-source and offline-first, with syncing capabilities allowing users to work seamlessly in settings with unreliable internet access. It allows health workers to track individual patients over time, providing clinical support and enabling consistent, long-term management of patient conditions in hospitals, health centres, clinics and in the field. Tamanu is developed specifically for remote contexts and meets the five principles of eHealth we consider to be fundamental to success: 1. Completely free and open-source, with no licensing costs. 2. Sync-enabled - able to work completely offline when the internet is slow or unavailable and syncing data when the internet is available. 3. Industry-standard data security, including encryption in transit and on the disk. 4. Desktop and mobile enabled, out-of-the-box, without requiring any third-party integrations. 5. Interoperable with existing systems (including mSupply, DHIS2 and Tupaia) and standards (including ICD-10, CPT etc which can be selected and configured within minutes).