Standard Edition and Enterprise Edition servers share the same software requirements.
Servers running Lync Server 2013, Enterprise Edition are intended for large organizations as the main organizational deployment. Enterprise Edition server is designed to scale to approximately 80,000 homed users per pool.
Servers running Lync Server 2013, Standard Edition are intended for smaller organizations and remote locations from the main organization deployment with a user count of approximately 5000 homed users.
Standard Edition and Enterprise Edition server can use any of the following:
-Windows Server 2008 R2 SP1 or latest service pack
-Windows Server 2012
Note: Lync Server 2013 is available only in a 64-bit edition, which requires 64-bit hardware and a 64-bit edition of the Windows Server operating system. A 32-bit edition of Lync Server 2013 is not available with this release.
-In all server roles, you must also make sure that Windows PowerShell command-line interface 3.0 and Microsoft .NET Framework 4.5 are installed.
-Additionally, Windows PowerShell command-line interface 3.0 and Microsoft .NET Framework 4.5 are required on any computer where you will run the Lync Server administrative tools.
Note: In addition to the updates required for the operating system, Lync Server 2013 requires operating system roles, features, and software to operate. For details about the additional software that must be installed prior to publishing your topology and installing Lync Server 2013, see Additional Software Requirements in the Planning documentation on Technet.