A new extension to VMM is the OVF Import/Export tool that consists of cmdlets that enable VMM 2012 users to import and export virtual machines that are packaged in the OVF format. You can use the OVF Import/Export tool to import a virtual machine from other virtualization platforms (currently VMware vCenter and Citrix XenServer) or to export a virtual machine for use on another platform.
The OVF format uses an XML file with the extension .ovf together with one or more virtual disks. The OVF Import/Export tool does not convert virtual hard disk file formats. You may need third-party tools to convert a virtual hard disk format.