Newer computingareas like peer-to-peer,grid, and service-orientedcomputing provide a number of opportunities and challenges for architectures of future digital libraries. Peer-to-peer data management allows for loosely coupled integration of information services and sharing of information such as recommendations and annotations. Grid computing middleware is needed because certain services within digital libraries are complex and computationally intensive, e.g., extraction of features in multimedia d- uments to support content-based similarity search or for information mining in b- medical data. The service-orientation provides mechanisms to describe the semantics and usage of information services and to combine services into work?ow processes for sophisticated search and maintenance of dependencies. Elements of all three directions should be combined in a synthesis for future digital libraries architectures. This volume contains selected and revised papers from the Sixth Thematic Wo- shop of the EU Network of ExcellenceDELOS on Digital Library Architectures,which washeldin S. MargheritadiPula (Cagliari),Italy,24-25June2004.Thisworkshopwas co-located with the 12th Italian Symposium on Advanced Database Systems (SEBD 2004) and organizedjointly by the DELOS Network of Excellence and the Department ofInformationEngineeringoftheUniversityofPadua,Italy. DELOS(http://www.delos.

This volume comprises papers from the following ?ve workshops that were part of the complete program for the International Conference on Extending Database Technology (EDBT) held in Heraklion, Greece, March 2004: * ICDE/EDBT Joint Ph. D. Workshop (PhD) * Database Technologies for Handling XML-information on the Web (DataX) * Pervasive Information Management (PIM) * Peer-to-Peer Computing and Databases (P2P&DB) * Clustering Information Over the Web (ClustWeb) Together, the ?ve workshops featured 61 high-quality papers selected from appr- imately 180 submissions. It was, therefore, dif?cult to decide on the papers that were to beacceptedforpresentation. Webelievethattheacceptedpaperssubstantiallycontribute to their particular ?elds of research. The workshops were an excellent basis for intense and highly fruitful discussions. The quality and quantity of papers show that the areas of interest for the workshops are highly active. A large number of excellent researchers are working on the aforementioned ?elds producing research output that is not only of interest for other researchers but also for industry. The organizers and participants of the workshops were highly satis?ed with the output. The high quality of the presenters and workshop participants contributed to the success of each workshop. The amazing environment of Heraklion and the location of the EDBT conference also contributed to the overall success. Last, but not least, our sincere thanks to the conference organizers - the organizing team was always willing to help and if there were things that did not work, assistance was quickly available.

These post-proceedings contain the revised versions of the accepted papers of the international workshop \Transactions and Database Dynamics," which was the eighth workshop in a series focusing on foundations of models and languages for data and objects (FoMLaDO). Seven long papers and three short papers were accepted for inclusion in the proceedings. The papers address various issues of transactions and database dynamics: { criteria and protocols for global snapshot isolation in federated transaction management, { uni ed theory of concurrency control and replication control, { speci cation of evolving information systems, { inheritance mechanisms for deductive object databases with updates, { speci cation of active rules for maintaining database consistency, { integrity checking in subtransactions, { open nested transactions for multi-tier architectures, { declarative speci cation of transactions with static and dynamic integrity constraints, { logic-based speci cation of update queries as open nested transactions, and { execution guarantees and transactional processes in electronic commerce payments. In addition to the regular papers, there are papers resulting from two working groups. The rst working group paper discusses the basis for transactional c- putation. In particular, it addresses the speci cation of transactional software. The second working group paper focuses on transactions in electronic commerce applications. Among others, Internet transactions, payment protocols, and c- currency control and persistence mechanisms are discussed. Moreover, there is an invited paper by Jari Veijalainen which discusses tr- sactional aspects in mobile electronic commerce.