Social Software are programs that promote interpersonal communication with interactive, computer-based social structures. Proponents claim that social software facilitates meaningful social ties through computer-mediated interaction. These interactions can potentially develop into larger online, internet, or real-life communities. Examples of Social Software are internet discussion forums, blogs, instant messaging (AOL Instant Messenger), and wikis. This type of software primarily facilitates communication without any physical presence. Although skype or video conferencing use voice or picture, social software does not necessarily require anything more than text. Due to this, the ideas of a relationship, friendship or acquaintence are changing. There is much debate about whether or not relationships facilitated primarily through social software are weaker, stronger, more or less personal or merely different from those developed in more traditional ways (i.e. face-to face). Regardless, social software is a major part of modern communication and technology, allowing for long distance correspondence in a variety of ways, both impersonal and personal.
Social software communication has become very popular with sites like MySpace and Facebook, media websites like Flickr and YouTube, and commercial websites like Amazon and eBay. Many of these applications allow you to design and customize your design of the site and also upload data and media. Many people who use these tools believe and trust that they create real communities, and have named sites like these "online communities" to describe the social atmosphere they create
http://en.wikipedia.org/wiki/Social_software "Wikipedia:Social Software"