We are witnessing a significant evolution in the scale and nature of computing systems, with great amounts of resources that currently remain largely unharnessed, uncontrolled, and isolated. Already, research and industry are starting to approach this new reality, notably by the "cloud computing" initiative that investigates new problems and lays down conceptual foundations for federating the vast populations of computing, storage, data, and software resources. The challenge is to federate this power and to control complexity: exploiting parallelism, distribution and heterogeneity; facilitating collaborative and self organizing behavior; easing resource sharing; ensuring security; etc.. The MistNet project will propose an easy-to-use, end-to-end, system-wide approach to cloud management and operation. As part of a just completed SNF project, the Institute of Computer Science at UniNE has developed a generic deployment infrastructure named Splay (www.splay-project.org), which forms a sound basis to building an experimental cloud platform: lightweight server virtualization, sandboxed and OS-agnostic execution environment, networking libraries, etc. The goal of MistNet is to design and implement the next generation of Splay, with novel extensions, enhancements, and services dedicated to supporting cloud applications. The planned MistNet platform will be both an infrastructure and associated services for a lightweight experimental cloud. MistNet will address several key challenges, among which one can highlight (1) the development of high-level facilities for designing distributed data structures, and mapping these structures over the physical networked cloud, hence forming overlay networks tailored to the actual application needs, and (2) the design of new mechanisms for fully decentralized and dynamically scalable storage facilities for applications operating on the cloud, with focus on low latency, high availability, privacy and security. The final outcome of the project will consist of a service-oriented peer-to-peer architecture with dedicated support for communication and overlay management, data storage, and code execution that will greatly ease the use of cloud computing platforms.