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Fed-X: The NIST Express Translator



Steve Clark


Fed-X, the NIST (Federal) Express Translator, and the associated Express Working Form, are Public Domain tools for manipulating information models written in the Express language. The Working Form is part of the NIST PDES Toolkit. It is intended to be used to provide the input to various conceptual-schema-driven applications in a PDES implementation. For example, tools such as QDES, a prototype STEP model editor developed at NIST, and the STEP parser STEP physical file parser and its associated STEP Working Form have been written independently of any particular data model, and Fed-X translators used to provide the information model definitions to drive these applications. This approach results in smaller applications (which need not have an entire information model embedded within them), as well as insulating these applications against changes in the conceptual schemas. Indeed, an applications such as STEPparser can be used with different conceptual schemas, or different versions of the same schema, without modification. QDES has been used to edit STEP product models in the context of several different Express information models.
NIST Interagency/Internal Report (NISTIR) - 4371
Report Number


Express Translator, STEP, WDES, PDES Toolkit


Clark, S. (1990), Fed-X: The NIST Express Translator, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed April 22, 2024)
Created January 1, 1990, Updated November 10, 2018