An overview on a lot of the thinking around social software, specifically a "quick way in to pick the most appropriate ideas for people in other fields". I like this definition:
Social software's purpose is dealing with with groups, or interactions between people. This is as opposed to conventional software like Microsoft Word, which although it may have collaborative features ("track changes") isn't primarily social. (Those features could learn a lot from social software however.) The primary constraint of social software is in the design process: Human factors and group dynamics introduce design difficulties that aren't obvious without considering psychology and human nature.Interconnected: Entry 2004/04/28/on_social_software
My own goes like this:
"Software designed to work the way people already do"
It's a little awkwardly worded, but I hope it captures the concept of software (and all of technology) as an enabler, a supporter for richer human connections, communication, and collaboration in the "real world".
It means that you need to have an understanding of how people use tools and what their needs are, and what the needs of different groups are going to vary.
And it means you need to design some of these thoughts in from day one.