by Frédéric Desprez, Ottmar Krämer-Fuhrmann and Ramin Yahyapour
The fast evolution of hardware capabilities in conjunction with fast wide area communication and availability of virtualization solutions is allowing new operational models for information technology. The advent of Cloud computing has resulted in access to a wide range of services. Infrastructure-as-a-Service (IaaS) allows access to large-scale resources like computational power or storage. These large scale platforms, based on huge datacentres, are available to industrial users as well as to scientific communities. IaaS allows the use of a large number of bare machines on which any software stack can be installed. The Platform-as-a-Service (PaaS) model provides the programmer with sets of software elements than can be combined in a scalable way to build large scale applications. Finally, Software-as-a-Service (SaaS) simplifies access to large applications in a remote and seamless way.