Advanced concepts for next generation portals

Over the last two years, portal sites surfaced as a major trend in electronic commerce. Unlike many other exaggerated trends, portals have become an important facet of the World Wide Web which is likely to stay. Emerging from search engines and catalogues, they integrate an increasing amount of information and functionality. The paper reflects on portal characteristics as well as on foundations of their realization and introduces technology needed for the next generation service trading concepts: based on the promising open source project Jetspeed, a prototype of the GIBRALTAR service portal is introduced, capable of integrating, trading and composing complex remote e-services.