With this paper a new approach for MEMS design tools will be introduced. An analysis of the design tool market leads to the result that most of the designers work with large and inflexible frameworks. Purchasing and maintaining these frameworks is expensive, and gives no optimum support for MEMS design process. The concept of design assistants, carried out with the concept of interacting software components, denotes a new generation of flexible, small, semi-autonomous software systems that are used to solve specific MEMS design tasks in close interaction with the designer. The degree of interaction depends on the complexity of the design task to be performed and the possibility to formalize the respective knowledge. In this context the Internet as one of today's most important communication media provides support for new tool concepts on the basis of the Java programming language. These modern technologies can be used to set up distributed and platform-independent applications. Thus the idea emerged to implement design assistants using Java. According to the MEMS design model new process sequences have to be defined new for every specific design object. As a consequence, assistants have to be built dynamically depending on the requirements of the design process, what can be achieved with component based software development. Componentware offers the possibility to realize design assistants, in areas like design rule checks, process consistency checks, technology definitions, graphical editors, etc. that may reside distributed over the Internet, communicating via Internet protocols. At the University of Siegen a directory for reusable MEMS components has been created, containing a process specification assistant and a layout verification assistant for lithography based MEMS technologies.