CAiSE'2007 was the 19 th in the series of International Conferences on Advanced Information Systems Engineering. This year's conference was located in Trondheim and hosted by the Norwegian University of Science and Technology (NTNU), with the aim of bringing together practitioners and researchers in the field of information systems engineering. The CAiSE series thereby returned to the city where the third CAiSE conference was held, in 1991.

Since the first CAiSE was organised in Stockholm in 1989, CAiSE has grown to become one of the most prestigious international conferences in the intersection between information systems, software engineering, database technology and several related fields. The conferences present basic and applied research results from academia alongside keynotes and research presentations from industry.

The special theme of CAiSE'07 was Ubiquitous Information Systems Engineering, reflecting that modern information systems often span activities performed in several organisations and at different geographical locations. They often support the untethered mobility of their users. The systems have already today a large impact on every day life in the organisations and on the individuals. As we move towards ambient, pervasive, and ubiquitous computing, this impact will increase significantly.

The CAiSE Forum aims at introducing an Agora for the presentation of fresh ideas, new concepts, experience reports on application experiences and project reports, as well as demonstration of new and innovative systems, tools and applications.

Whereas CAiSE'07 invited general submissions on the development, maintenance, procurement, and usage of information systems, submissions dealing with aspects related to information systems engineering in ubiquitous environments were therefore especially welcome. The response was overwhelming. 301 papers were submitted, which was a new record for the CAiSE conferences. This year, there was no separate call for papers to the CAiSE Forum. Instead, Forum papers were selected among very good submissions with new interesting ideas, concepts which, however, were still a bit "rough on the edges" and therefore just fell short of making it into the top 40 accepted for the main conference. 39 papers were invited to the Forum where 23 of these are included in this volume. The most correct estimate for the acceptance ratio of Forum papers would thus be (#main conference papers accepted + # forum papers accepted) / # submissions in total = (40+39) / 301 = 26%.

Finally, we wish to thank our sponsors that helped, with their support, the organization to offer a nice environment and enjoyable services, while keeping the fees in a reasonable range.