The total product design process consists of several stages including the formulation of product design specifications, conceptual design, detail design, manufacture and sales. In recent years, the rapid development of computer technologies has greatly impacted the product development process. In the engineering area, powerful computer-based tools such as Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) systems enable engineers to fulfil various tasks in individual stages such as conceptual and detail design, and manufacturing simulation. However, the increasing complexity of modem products, cruel competition pressure and the globalisation of product development necessitate a collaborative design environment where distributed computer programs and dispersed experts in similar or different domains could be collaboratively involved in a common design activity, in order to obtain high quality and low cost product design. The key issues for establishing such a collaborative environment are the integration and communication of the computerised design resources with heterogeneity and distribution features. The collaborative architecture presented in this thesis employs a combination of CORBA with other technologies such as Java, Genetic Algorithms to integrate engineering design programs and to enable communication between them, regardless of languages they are written in and platforms they are ported on, and to leverage multiple design interests. The resultant Web-based architectures have identified and addressed three main application paradigms. Firstly, by using CORBA-Servlet, a singular large-size program can be executed remotely with interactive features such as parameter input, program execution and monitoring, and varieties of dynamic and rich forms of resultant return. The developed system also facilitates multi-user management. Secondly, Genetic Algorithms has been employed to combine the CORBA to mediate the impacts from different domain expert considerations over the distributed environment. In this environment, CORBA is used as an architecture for integrating multiple design applications that are heterogeneous and distributed and for enabling them to communicating with each other, a GA-based optimiser is designed to help a main designer to conduct gear design optimisations through invoking remote and heterogeneous applications to meet user's complex needs. Thirdly, Applet-CORBA based system is developed to provide a thin client model to enable users to do the remote invocation from a Web browser, without any setting up for CORBA in advance. As a user of this application, a designer does not need to get to know anything about CORBA. The rich features of applet allow client developers to design varieties forms of Web browser application, such as dynamic data, dynamic drawing, and so on. It is found that functionalities of traditional, stand-alone, single-user computer-aided applications can be extended by employing modem distributed object computing and web technologies. These technologies provide cornerstone and effective support in building scalable, extensible, and interactive distributed systems for collaborative design, as illustrated in demonstration systems developed in the present thesis.