TEAA 2005 (Trends in Enterprise Application Architecture) took place as a workshop of the conference VLDB 2005 (31st International Conference on Very Large Databases) in August 2005 in Trondheim, Norway. Enterprise applicationsare mission criticalfor organizations.Currently there are several initiatives that see enterprise application integration as their natural playground, like Model Driven Architecture and Service Oriented Architecture. Now is the time to investigate how these approaches can provide added value. At TEAA 2005 the contributions identified a problem or issue in enterprise application architecture and proposed and evaluated a solution. The workshop benefited from lively discussions among the participants. Applications, operating systems, database systems, hardware architecture and system administration concepts must be orchestrated to yield an optimized systemarchitecturethat tacklesperformance,stability,security,maintainability, andtotalcostofownership.Inpractice,itisalwaysaholisticviewthatisneeded – it is known that system design approaches that overemphasize one of the software or hardware architecture aspects are likely to fail. In the TEAA 2005 workshop we examined the conceptual underpinnings of enterprise application architecture. We are grateful to our keynote speaker Laura Haas for sharing her insights with us.