CloudShare alternatives

CloudShare
CloudShare provides a secure, self-service public cloud that extends internal IT capabilities. CloudShare enables you to build complete production-like environments in minutes. Deliver fully-functional demos, proof-of-concepts, and evaluation environments on demand and online. Provide effective hands-on technical training to employees, partners, and customers. Create virtual environments while gaining access to IT resources at the speed of agile development.
CloudShare alternatives are:
Amazon Web Services, Windows Azure, Skytap