Layered Manufacturing is a valuable tool for efficient and concurrent engineering. In order to maximize its effectiveness, a web-based user-friendly virtual design and fabrication system has been developed using a systematic knowledge-based approach. The large amount of information available on layered manufacturing has been organized into a modular format. Tables and appendices organize hardware and software information for the different methods. A linked dictionary defines unfamiliar terminology. Java applets allow users to create an individualized engineering specification for their part. Recommendations regarding machines and materials are made based on this input. Tutorials guide the LM build process from initial design through selection of build parameters. This comprehensive knowledge base will expose the individual to various rapid prototyping concepts, and should reduce the build iterations required to successfully build parts. The web pages concentrate mainly on stereolithography and fused deposition modeling, but provide introduction to other technologies. Due to the quickly developing nature of the RP industry, information changes periodically. With the modular structure, as new materials and technologies become available, their information can be easily added to the existing knowledge base. Industry feedback on the web site development is facilitated via an online guestbook.