SOM is the object technology used for the implementation of the Workplace Shell. It provides a language neutral, object-oriented programming methodology that you can use to create Workplace Shell objects and bind them to the Workplace Shell. This chapter describes SOM's architecture, its features and environment. It describes its methods, classes, and finally provides an example of its workings. This chapter is not intended to be a SOM programming guide. It is, however, intended to serve as an introduction to SOM at a level necessary to write Workplace Shell applications.