Elgg is an open, flexible social networking engine, designed to run at the heart of any socially-aware application. Building on Elgg is easy, and because the engine handles common web application and social functionality for you, you can concentrate on developing your idea.

Elgg is open source. That means, when you use Elgg, you have the benefit of being part of a large developer community, with the security and stability that hundreds of eyes can provide. It’s also headed and used by Curverider and its partners, so you can be assured that it’s in commercial use and will cope with the demands of a popular application. 

It runs on Apache, PHP and MySQL – the same open source platform that the majority of web applications are written in. Elgg is compatible with enterprise technologies like the Zend Platform and any server environment that can run the Apache web server.

Elgg supports

• User, object, file and site management
• Social graph functionality (relationships between users and other users, objects and sites)
• Multiple sites (or applications) per installation
• Easy internationalisation support
• System-wide, tag-based searching across all content and users
• Fine-grained access controls
• Multiple views, allowing for mobile applications and embeddable widgets as well as the traditional web browser view
• Event, plugin and widget APIs

Technical, back-end features

• RSS, FOAF, XFN for content syndication
• OpenID, OpenSocial, OAuth for integration with other web services
• Open Data Definition and an increasing number of data portability formats for import / export
• An extensible RESTful API, with results in JSON, serialised PHP or XML
• AJAX through jQuery and user-definable callbacks
• Easy extension for use with caching systems such as memcached, for increased system performance
• Use of multiple database connections for scalability

End-user features