Wikipedia
PBworks
PBworks (formerly PBwiki) is a commercial real-time collaborative editing (RTCE) system created by David Weekly, with Ramit Sethi and Nathan Schmidt, who joined shortly thereafter as co-founders. Based in San Mateo, California, United States, the company operates on a freemium basis, offering basic features free of charge and more advanced features for a fee.
PBworks' investors include Mohr Davidow Ventures and the Seraph Group, as well as angel investors Ron Conway and Chris Yeh.