Parametric feature-based CAD data exchange is one of the most important open problems in solid modeling. The problem is significant and challenging both scientifically and commercially. In this paper we present a very general outline of the Universal Product Representation (UPR) architecture, which provides universal support for all data levels employed by today’s CAD systems. The architecture has been implemented with successful results. Categories and Subject Descriptors D.2.11 [software architectures]: domain specific architectures; D.2.12 [interoperability]: data mapping; I.3.5 [computational geometry and object modeling]: Breps, CSG, solid, and object representations, geometric languages and systems; I.3.6 [methodology and techniques]: graphics data structures and data types, languages, standards; J.2 [physical sciences and engineering]: engineering; J.6 [computer-aided engineering]: CAD, CAM. General Terms Design, Standardization, Languages, Verification. Keywords CAD Data...