Appwrite - ~15.7K stars
- Docker based
- Realtime support across all services
- Advanced security features (virus-scanning, data encryption, auto SSL, rate-limiting)
- Cross-platform: supports Web, Flutter, Desktop, Mobile and backend - over 10 SDKs: https://appwrite.io/docs/sdks
- Cloud Functions with +15 runtimes in multiple languages
Parse Server - ~16K stars
- javascript based
- mongodb or postgres database