Social software encompasses a range of software systems that allow users to interact and share data.

This computer-mediated communication has become very popular with social sites like MySpace and Facebook, media sites like Flickr and YouTube as well as commercial sites like Amazon.com and eBay.

Many of these applications share characteristics like open APIs, service-oriented design and the ability to upload data and media. The terms Web 2.0 and (for large-business applications) Enterprise 2.0 are also used to describe this style of software.