What is Elgg ?

hello friends,

I am not sure whether I am posting this question in the right section or not. I have recently heard about the term called Elgg.
What is Elgg ? Is it software or something else ? can somebody help me providing information and details about this ?

thnx

Elgg is a white label, open source social networking platform. It offers blogging, networking, community, collecting of news using feeds aggregation and file sharing features. Everything can be shared among users with access controls and everything can be cataloged by tags as well.

Elgg has a book titled "Elgg Social Networking" written by open source journalist Mayank Sharma.

Elgg had gained a lot of traction in the educational sphere, where it has been used to power social networks for various institutions and organisations:

Elgg is social networking software designed especially for education - built from the ground up to support learning.

Elgg provides each user with their own weblog, file repository (with podcasting capabilities), an online profile and an RSS reader. Additionally, all of a user's content can be tagged with keywords - so they can connect with other users with similar interests and create their own personal learning network. However, where Elgg differs from a regular weblog or a commercial social network (such as MySpace) is the degree of control each user is given over who can access their content. Each profile item, blog post, or uploaded file can be assigned its own access restrictions - from fully public, to only readable by a particular group or individual.