Stock Exchange transactions constitute a sequence of highly complicated processes performed in an extremely dynamic environment. Furthermore, there are a large variety of different marketplaces for trading stocks across Europe, each featuring unique characteristics. The recent Directives of the EC have also imposed the need for the development of a fast and unifying network for financial transactions for all European capital markets. This project called Terminal at High speed for European Stock Exchange Users, or briefly the THESEUS, is a breakthrough development for European Stock Exchange markets. The terminal constitutes the primary building block of a robust network system that is designed not only to meet the current requirements of Stock Exchange users but to exceed them as well. Based on the capability of existing automated teller machines (ATM) to merge service protocols, the system interconnects incompatible networks without affecting the already operating software. This terminal is the connecting link between Stock Exchanges and remote users for supporting trading applications, supplying ATM access and adapting the existing Stock Exchange front ends to the ATM protocols. Since the terminal features multi-window display software, it allows its users to view information exchanged between several Stock Exchanges and their brokers on a single screen without additional applications needed. In addition, it is also capable of supporting video conferencing services for the trading application. Depending on its application purposes, the terminal comes in two versions, the basic and the multimedia. With its capabilities, the system will enable the efficient and effective implementation of the EC directives promoting the concept of the unified European capital market. By improving the quality of the trading transactions, the system will also enhance the productivity of the European financial industry, making it more competitive against other global markets.