A concept originated by the architect Christopher Alexander. It refers to a set of repeated patterns, on a wide range of scales, that apply in urban design and architecture. In the 1990s this idea was taken up by software developers, who found repeated patterns in the software they were writing. The same concept can be applied to time: though history never repeats itself exactly, the same general patterns occur again and again. Thus there can be a pattern language of event sequences. See event sequence analysis.
an encyclopedic study of what makes buildings, streets, and communities work -- indeed, what makes environments human