To survive in today's economy; short time-to-market and efficiency are paramount for the creation of innovative products and to survive in the current economic climate. This is especially true for IT services which will dominate the way people work and live in the future.Cloud computing is essentially changing the way services are built, provided and consumed. Despite simple access to Clouds, building elastic services is still an elitist domain and proprietary technologies are an entry barrier especially to SMEs and consequently, it remains largely within the domain of established players.To accelerate the creation of highly demanded tailored services in a timely manner, the Cloud paradigm requires major change to address the way services are built, provided and accessed. Abstracting from technical complexities lowers entry barriers and empowers SMEs in especial, to offer applications to this significant market without large upfront investments.The project envisions:An Internet-scale application platform for design, operation, management, and trading of services and service compositions which can be tailored to different local or global communities.4CaaST will provide benefits and business opportunities for the following stakeholders:• Application Providers can focus on building applications integrating the latest IT and Telco interaction (NaaS) paradigms. Particular emphasis will be paid to scalability, lifecycle and resource management.• Platform Providers can instantiate and efficiently operate a 4CaaST platform as a service and can establish an eco-system via the 4CaaST marketplace.• Service Aggregators can focus on value added services through composition and mashup.The project will bring significant benefits to the European economy. It will provide an easy to use Infrastructure for a More Competitive Environment, greatly simplifying design and delivery of tailored services and compositions.