Social software, also known as Web 2.0 applications or social apps, include communication tools and interactive tools often based on the Internet. Communication tools typically handle the capturing, storing and presentation of communication, usually written but increasingly including audio and video as well. Interactive tools handle mediated interactions between a pair or group of users. They focus on establishing and maintaining a connection among users, facilitating the mechanics of conversation and talk. Although we do not have a generally accepted definition but by social software we mean software that makes collaborative behaviour, the organisation and moulding of communities, self-expression, social interaction and feedback possible for individuals. Another important element of existing definition of "social software" is that it allows structured mediation of opinion between people, in a centralized or self-regulating manner. The most improved area for social software is that Web 2.0 applications can all promote cooperation between people and the creation of online communities more than ever before.

In philosophy and the social sciences, social software is an interdisciplinary research program that borrows mathematical tools and techniques from game theory and computer science in order to analyze and design social procedures. The goals of research in this field are modeling social situations, developing theories of correctness, and designing social procedures.