11
 Evolution of Patterns
–Erich Gamma’s doctoral thesis described the patterns incorporated in ET++, a GUI application framework
–Since 1991, workshops have been held each year in conjunction with OOPSLA to discover and document design patterns
–The book Design Patterns by Gamma, Helm, Johnson, and Vlissides (the gang-of-four) was published in 1995.  It describes twenty-three design patterns
–Other books are now being published that present additional patterns and patterns in other domains.