Citrix Receiver runs on Microsoft Windows. This should come as no surprise as Windows has been the deployment model for Citrix ever since its inception as a company.
Citrix Receiver is compatible with the following Windows versions:
Windows Server (2012 R2, 2012, 2008 R2, 2008)
Windows desktop (Win 8.1, Win 8, Win 7, Vista, XP)
Windows 8/RT
Windows CE
Windows Phone 8