Office Web Apps has now been split out to a completely separate server product loosely based on SharePoint but no longer reliant on it, in reality it is now the opposite. Lync and SharePoint 2013 need Office Web Apps 2013 deployed and available to get full functionality for Web viewing of files.To start with wee need to install the following pre-requisites using PowerShellFor Windows 2012Add-WindowsFeature Web-Server,Web-Mgmt-Tools,Web-Mgmt-Console,Web-WebServer,Web-Common-Http,Web-Default-Doc,Web-Static-Content,Web-Performance,Web-Stat-Compression,Web-Dyn-Compression,Web-Security,Web-Filtering,Web-Windows-Auth,Web-App-Dev,Web-Net-Ext45,Web-Asp-Net45,Web-ISAPI-Ext,Web-ISAPI-Filter,Web-Includes,InkandHandwritingServicesFor Windows 2008 R2Add-WindowsFeature Web-Server,Web-WebServer,Web-Common-Http,Web-Static-Content,Web-App-Dev,Web-Asp-Net,Web-Net-Ext,Web-ISAPI-Ext,Web-ISAPI-Filter,Web-Includes,Web-Security,Web-Windows-Auth,Web-Filtering,Web-Stat-Compression,Web-Dyn-Compression,Web-Mgmt-Console,Ink-Handwriting,IH-Ink-SupportThen we also need to install .NET 3.5 otherwise we will get some Lync presentation issues later on.Now we can run through the installation by running Setup.exe from the install media.Agree to the licensing terms, choose an install location and let it rung through.Once installed we can create and configure our OWA Farm using PowerShellImport-Module OfficeWebApps New-OfficeWebAppsFarm –InternalURL http://servername -ExternalURL https://FQDN -CertificateName “Certificate Friendly Name” –AllowHttp -EditingEnabledNB – Editing requires licensing, view only is free.NB – Certificate requires the unqualified and FQDN specified in the Subject Alternate Name field.To test that everything is OK we can navigate in a browser to http://servername/hosting/discovery or https://FQDNservername/hosting/discovery we should get returned an XML output with no certificate errors.Further information can be found on TechNet here