Inhaltsangabe:Abstract: There are about 230.000 establishments in the Spanish hotel, restaurant and catering industry accounting for a turnover of about 15.6 thousand million euros. All of them sell food to private consumers. On the other hand suppliers and traders supply the catering trade with food and beverage products. Usually the different players in this food distribution network trade products by means of orders which are placed manually. This is a process which can be enhanced through the application of computer and Internet technology. A project lately also supported by the Spanish government is supposed to fill this gap. This project is called Catanet and has been established three years ago. Actually the Catanet platform is used by more than 100 customers, amongst them very important industry players like Lauren Films, Pepsi, Unilever and Nestle. Some of them will carry out a significant part of their overall food orders by the Catanet platform, which corresponds to a turnover volume of many million euros. In the former version of the Catanet platform clients had to apply a web page based interface in order to use the Catanet services. As this approach prohibited the full exploitation of the benefits the use of computer assistance provides (e.g. human participation still constitutes an inevitable and crucial part of the transaction, the interaction is completely asynchronous) an additional level is being added to the Catanet platform eliminating these shortcomings. During the time of this work the number of Catanet customers has grown explosively increasing also the diversity of the customer s computer systems. Additionally new subprojects could be launched due to the acquisition of a government grant. These encompassed among others new value added services demanded by the customers like an instant messaging module and a module for the automatic update of the local product catalogue. The characteristics of the IT infrastructure of the new customers which will carry out transactions with a serious turnover via the Catanet platform and the necessity to integrate the new subprojects required an adaptation of the design of the platform prototype which had been developed by this time and which is described in this work. Within this context the decision has been done to use .NET Framework based programs on the customer side instead of Java which had been used so far. The reasons for this were besides the easier integration with the IT [...]