Given the inevitable trends towards increasing complexity of software-intensive systems, many future software-intensive systems will be ultra-large scale (ULS). Radical scale-up of systems will be manifested in many dimensions: implementation complexity, distribution, decentralization, networking, storage, and quality-of-service, dependability/security, size and structure of development organizations and methods, complexity of organizations surrounding deployed systems, and so forth. Radical increases in scale and complexity will demand new approaches to all aspects of system conception, definition, development, deployment, use, maintenance, evolution, and regulation. This workshop, the First ICSE Workshop on ULS systems, has several goals: to raise awareness of ULS systems in the ICSE community; to further our understanding of the characteristics of such systems; to explore the unique research problems of ULS systems; to help foster a community who study and build ULS systems; and to understand the role and the shortcomings of traditional software engineering concepts, methods, and tools relative to ULS systems.