See also Next Interface Builder
Graphical Editor for designing user interface components. Part of Next Step. Now used in Apple's Mac Osx as part of Ex Code.
See: developer.apple.com 
The Next Step 3.3 documentation is available here: www.channelu.com
Interface Builder was first written in Lisp by Jean Marie Hullot in 1984 and commercialized in 1986 (though its first incarnation may have been named "SOS Interface".) Hullot was hired by NeXT, Inc. where he created a similar tool for Objective Cee and the Next Step, launched in 1989. Meanwhile, Rick De Natale was inspired by Interface Builder to write Visual Age, the Smalltalk IDE that became the Eclipse Ide. See www.diigo.com
See original on c2.com