Real world engineering design projects require the cooperation of multidisciplinary design teams using sophisticated and powerful engineering tools. The individuals or the individual groups of the multidisciplinary design teams work in parallel and independently with the different engineering tools which are located on the different sites for often a long time. In order to ensure the coordination of the design activities of the different groups or the cooperation among the different engineering tools, it is necessary to develop an efficient distributed intelligent design environment. This paper discusses a distributed axchitecturc for integrating such engineering tools in an open design environment organized as a population of asynchronous cognitive agents. Before introducing the general architecture and the communication protocol, issues about the agent axchitecture and the inter-agent communication are discussed. A prototype of such an environment with seven independent agents located in the different workstations and microcomputers is presented and an example of a small mechanical design is used for demonstrating such an environment.