As part of an enterprise effort to develop new clinical information systems at Intermountain Health Care, we have built a Knowledge Authoring Tool that facilitates the development and refinement of medical knowledge content. At present, users of the application can compose order sets and an assortment of other structured clinical knowledge documents based upon XML schemas. The flexible nature of the application allows for the immediate authoring of new types of documents once an appropriate XML schema and accompanying web form have been developed and stored in a shared repository. The need for a knowledge acquisition tool stems largely from the desire for medical practitioners to be able to write their own content for use within clinical applications. We hypothesize that medical knowledge content for clinical use can be successfully created and maintained through XML-based document frameworks containing structured and coded knowledge.