Citrix XenApp

Software from Citrix that provides a thin client, multiuser environment for Windows servers. Formerly WinFrame Server, MetaFrame Server and Presentation Server, Citrix developed this software years ago for Windows NT. See WinFrame and thin client.

Streaming Applications
XenApp provides "local application delivery" by streaming the application as needed to the Citrix Receiver software in the user's machine. XenApp can also integrate with and add more options to Microsoft's own App-V application streaming. See application streaming and App-V.

Thin Client Terminal Access
Also known as "shared sessions," XenApp integrates with and adds numerous performance and management enhancements to Microsoft's Remote Desktop Services, starting with Windows Server 2008 R2, and to Terminal Services running in earlier Windows servers. XenApp also supports more types of client hardware than Microsoft and uses its own ICA protocol to exchange keyboard, mouse and screen data between the server and client terminals.

Also on Unix Servers
For a long time in the Unix world, X Window has provided shared terminal services. To integrate XenApp with Unix, XenApp sets up an X Window partition in the server for each user and converts between X Window and ICA. See X Window.

Citrix Created Multiuser Windows
In 1997, Citrix licensed its MultiWin technology to Microsoft and it became the underlying foundation in Terminal Services and, subsequently, the shared session component in Remote Desktop Services. See thin client, Terminal Services, Remote Desktop Services, centralized processing and Citrix XenDesktop.

XenApp Shared Session Mode

XenApp relies on the same Citrix foundation that Microsoft's thin client platform does, but XenApp uses the ICA protocol rather than Microsoft's RDP for transferring keyboard, mouse and screen data.