Cloud Computing has emerged as a new paradigm for deploying, managing and offering services through a shared infrastructure. The foreseen benefits of Cloud Computing are very compelling both from a cloud consumer and from a cloud services provider perspective: freeing corporations from large IT capital investments via usage-based pricing schemes; leveraging the economies of scale for both services providers and users of the cloud; easing the deployment of services.One of the main challenges to materialize these perceived benefits is to identify innovative distributed programming models that simplify the development of Cloud-based services, allowing for ordinary programmers to take full advantage of the seemingly unbounded amount of computational power and storage available on demand in large scale Cloud infrastructures.This project aims at designing, building, and evaluating an innovative middleware platform for service implementation of Cloud-based services: Cloud-TM (Cloud-Transactional Memory).Cloud-TM offers a simple and intuitive programming model for large scale distributed applications that integrates the familiar notion of atomic transaction as a first-class programming language construct, sparing programmers from the burden of implementing low level, error-prone mechanisms (e.g. locking, persistence and fault-tolerance) and permitting major reductions in the time and cost of the development process.Cloud-TM will embed a set of autonomic mechanisms to simplify service monitoring and administration, a major source of costs in dynamic and elastic environments such as the cloud.These mechanisms aim at ensuring the achievement of user defined Quality of Service levels at minimum operational costs by automating the provisioning of resources from the cloud and self-tuning the middleware platform to achieve optimal efficiency in the utilization of resources.