Formerly known as Windows Azure Services for Windows Server (a mouthful and not very meaningful), the Windows Azure Pack has been released with Windows Server and System Center 2013 R2. The goal of WAP is to bring the portal of Windows Azure, Microsoft’s public cloud, to the clouds of service providers and even on-premise private clouds. With WAP you can deploy the difficult to obtain trait of a cloud: self-service.
There appears to be a lot of information on WAP out there now.