Network Functions Virtualization (NFV) is an emerging concept, which refers to the migration of certain network functionalities, traditionally performed by hardware elements, to virtualized IT infrastructures, where they are deployed as software components. NFV leverages commodity servers and storage, including cloud platforms, to enable rapid deployment, reconfiguration and elastic scaling of network functionalities. With the aim of promoting the NFV concept, T-NOVA introduces a novel enabling framework, allowing operators not only to deploy virtualized Network Functions (NFs) for their own needs, but also to offer them to their customers, as value-added services. Virtual network appliances (gateways, proxies, firewalls, transcoders, analyzers etc.) can be provided on-demand as-a-Service, eliminating the need to acquire, install and maintain specialized hardware at customers/premises. For these purposes, T-NOVA will design and implement a management/orchestration platform for the automated provision, configuration, monitoring and optimization of Network Functions-as-a-Service (NFaaS) over virtualized Network/IT infrastructures. T-NOVA leverages and enhances cloud management architectures for the elastic provision and (re-) allocation of IT resources assigned to the hosting of Network Functions. It also exploits and extends Software Defined Networking platforms for efficient management of the network infrastructure. Furthermore, in order to facilitate the involvement of diverse actors in the NFV scene and attract new market entrants, T-NOVA establishes a "NFV Marketplace", in which network services and Functions by several developers can be published and brokered/traded. Via the Marketplace, customers can browse and select the services and virtual appliances which best match their needs, as well as negotiate the associated SLAs and be charged under various billing models. A novel business case for NFV is thus introduced and promoted.