Cloud computing is currently the most important trend in the Information and Communication Technology (ICT) industry, and it has still not fully realized its potential. Reasons for its popularity are the opportunities to rapidly allocate vast amounts of computing resources and the fact that resources are accounted per use. While cloud computing was initiated by major industry players, academia has rapidly caught up; currently we see a vast number of cloud computing-related research efforts. However, since industry pushes development and many research aspects of cloud computing demand for large compute resources and real workloads, pure academic efforts have difficulties to address the most important issues and to have a major impact. On the other hand, academia usually tends to explore disruptive ideas that would not be addressed by industry alone. This paper summarizes the approaches and methods of five EU-funded research projects that focus on cloud computing in general and address important issues such as security, dependability, and interoperability. These aspects have received limited attention by the industry so far. The key to success of these large joint efforts is the close collaboration between partners from academia and industry spread all over Europe. The specific projects are Cloud-TM, Contrail, mOASIC, TClouds and VISION Cloud. Besides presenting the individual projects and their key contributions, we provide a perspective on future ICT research in Europe.