
Elgg
Elgg is a modular open source platform for building social networks and collaborative communities with plugin-based extensions.

Elgg is an open source social networking engine that provides a robust framework for creating social environments such as campus networks, internal collaboration platforms, or brand communities. It emphasizes a plugin-driven architecture, a well-documented API, and a flexible content model that can be extended with plugins.
Key Features
- Well-documented core API with a gentle learning curve
- Composer-based installation and plugin management
- Hook and event system enabling plugins to extend functionality
- Extendable views for theming and presentation
- Client-side API with asynchronous modules for dynamic interactions
- Flexible entity system with a unified API layer for custom content types
- Fine-grained access control for private networks and user content
- Out-of-the-box Groups, Notifications, and file storage integration
- RPC web services for external integrations and mobile clients
- Internationalization and localization support
Use Cases
- Build campus-wide social networks or university intranets
- Create internal collaboration platforms for organizations
- Launch brand communities or client engagement portals
Conclusion
Elgg’s modular architecture makes it suitable for a range of social applications, from education to enterprise. It relies on PHP/MySQL and standard web servers, with a rich plugin ecosystem to tailor functionality.
