The Portland Pattern Repository (PPR) is a repository for computer programming design patterns. It was accompanied by a companion website, WikiWikiWeb, which was the World's first wiki.
The repository has an emphasis on Extreme Programming. It is hosted by Cunningham & Cunningham (C2) of Portland, Oregon at http://c2.com/ppr/. The PPR's motto is "People, Projects & Patterns."
On 17 September 1987 programmer Howard G. (Ward) Cunningham, then with Tektronix, and Apple Computer's Kent Beck co-published the paper Using Pattern Languages for Object-Oriented Programs. This paper about programming patterns was inspired by Christopher Alexander's architectural concept of "patterns". It was written for the 1987 OOPSLA programming conference organized by the Association for Computing Machinery. Cunningham's and Beck's idea became popular among programmers, because it helped them exchange programming ideas in a format that is easy to understand.
Cunningham & Cunningham, the programming consultancy that would eventually host the PPR on its Internet domain, was incorporated in Salem, Oregon on 1 November 1991 and is named after Ward and his wife Karen R. Cunningham, a mathematician, school teacher, and school director. Cunningham & Cunningham registered their Internet domain c2.com on 23 October 1994.
Ward created the Portland Pattern Repository on c2.com as a means to help object-oriented programmers publish their computer programming patterns by submitting them to him. Some of those programmers attended the OOPSLA and PLoP conferences about object-oriented programming, posting their ideas on the PPR and exchanging e-mail messages with Ward.
The PPR is accompanied on c2.com by the first ever wiki—a collection of reader-modifiable Web pages—which is called WikiWikiWeb and is located at http://c2.com/cgi/wiki.