REI3

REI3 is a free and open low-code platform for building and hosting business applications with full control and ownership. It targets organizations that want to replace spreadsheet-based solutions with proper multi-user apps, run them in the cloud or on-premise, and avoid walled gardens and cloud-only SaaS. Created applications can be used, shared or even sold.

Applications can summarize records, do date calculations and apply business rules, show tasks on Gantt charts, diagrams and dense lists, and include workflows such as forms that change with a record's state, PDF export and notifications. Roles and access policies restrict access globally or per record, and built-in end-to-end encryption comes with key management. Integration options include serving and calling REST endpoints, CSV import and export and ICS calendar access. The platform also covers mobile use with PWA features, full-text search, input types such as signatures and bar or QR code scanning, password policies and brute-force protection.

REI3 is written in Go and JavaScript, uses multi-core processing and bi-directional data channels for speed, and has downloads, documentation, a live demo and a catalog of applications. Its license is listed as Other.