Don Yacktman works for illumineX, inc., a company that specializes in Cocoa. His most visible project is the Misc Kit, a large collection of reusable Objective-C components.
He co-wrote an article with AlexDuongNghiem? in the July 1996 Object magazine discussing how design patterns can be applied to lessen the learning curve of NeXT's Web Objects Framework. He is also one of the authors of Cocoa Programming from Sams books.