An Organizational Memory is an enterprise-internal application-independent information and assistant system. It integrates various techniques and tools to support knowledge management. Motivated by the growing need for enterprise-wide knowledge management we performed several studies and identified the functional requirements for an Organizational Memory. To cope with these we propose a three-layered architecture for representing the knowledge. On this basis, the Organizational Memory shall serve as an intelligent assistant to the user and process both formal and non-formal knowledge elements in a task-oriented way. The concepts described here are the object of ongoing research, but are employed and tested in several application projects which run in parallel.