Windows Server 2012 is a cloud-optimized, highly dynamic, available, and
  cost-effective server platform. Download the free Windows Server 2012 trial
  to evaluate it for 180 days, with no feature limits.

Experience the next level of Microsoft’s server platform, including new virtualization
  and cloud capabilities, enhanced manageability, an exciting new open
  application and web platform, and the ability provide access to data and
  applications from virtually anywhere on any device. 

 http://technet.microsoft.com/en-US/evalcenter/hh670538.aspx