Within the last decade several new developments have contributed to many new opportunities, as well as to a need for intensive research and development. New applications are driven by the desire for ubiquitous high-quality access to offered and available services at reasonable cost. A considerable amount of research and development activities are currently going on world wide in order to adopt Internet services to the particular needs of users working in various environments and having an access to a great amount of information provided by commerce, business and public institutions. Expanding understanding and usage of Internet raise different technological problems and societal impacts. The emergence of the new societal environment created by Internet is a historical necessity; digitization becomes a correlate of most human activities nowadays including e-economy, e-medicine, e-government, etc. As a medium of communication the Internet reached a relative maturity, whilst as a new societal environment it is still in the making. The Internet produces an enormous and huge e-environment society requiring intermediaries who guide, search, integrate and authenticate knowledge and information. The 5th IFIP I3E'2005 proceedings contains a selection of 40 research contributions, which were extended to incorporate the numerous suggestions made by the itnernational reviewers. The papers in this volume address problems located in three main categories: e-commerce, e-business and e-government. Some of them are interdisciplinary and address problems common to the other mentioned areas.