The Macintosh Computer and its traditional OS had completely different design goals and user interaction than Unix systems. Because of compatibility with legacy applications, drastic changes to the core OS and Toolbox, to support a modern architecture that uses multitasking and memory protection, have failed in the past. But now the new MacOS X architecture has a compromise that combines the advantages of a Unix system with an advanced application development system and way to run old style Macintosh Applications on top of the modern OS. This is done using highly integrated modernized Macintosh Toolbox requiring only minimal changes to the sources of the old style MacOS 9 compatible applications. In the presentation an overview will be given on how this was achieved and more detailed some aspects that presented more technical challenges.

Serge Robe is Product Manager for Apple Europe Software. From '88-'97 he worked for Digital Equipment France & Europe, Technical Support Division as a Senior Consultant specialized on servers solutions with OpenVMS (clusters), OSF/1 and Digital Unix, then PATHWORKS for Macintosh Product Manager. Serge was also involved in European projects with Cray Research (Director of the European Cray/Digital Technical Support Center for the Y-MP-EL supercomputers). From '97-'99 he joined Apple Computer France where he was a Server solutions evangelist Since February 2000 Serge works for Apple Computer Europe