Open source - MIT license
Saltcorn is a full-stack builder platform for web and mobile database applications.
Saltcorn is suited to complex applications with many related database tables. A broad ecosystem of extensions allows builders to implement UI patterns (such as kanban boards, maps, rich text editors, calendars etc). Forms and database row views are built with a drag-and-drop builder.
Saltcorn is open source, released under the MIT license, and is suited to applications with strict privacy requirements. Saltcorn can be self-hosted, or DigitalOcean and Linode have on-click installers from their marketplaces.