Windows Management Framwork (WMF) 5.0 is now RTM. Currently, WMF 5.0 RTM is supported on Windows Server 2012 R2, Windows Server 2012, and Windows 2008 R2 SP1. You’ll need .NET Framework 4.5 installed to run WMF 5.0
WMF 5.0 RTM brings new management technologies such as Just Enough Admin (JEA), PowerShell Classes, PackageManagement, PowerShellGet, etc. and improvement to existing technologies such as Desired State Configuration (DSC), PowerShell Script Debugging, Software Inventory Logging (SIL) etc. to downlevel systems.