What is Citrix XenApp?

Citrix XenApp, now called Citrix Virtual Apps, was a product that extended Microsoft Remote Desktop Session Host (formerly known as Terminal Services) desktop sessions and applications to users through the Citrix HDX protocol.

XenApp and Remote Desktop Services allowed IT departments to centrally manage Windows applications and computing resources in a secure data center. Users could access the Citrix XenApp applications from anywhere and from non-Windows clients. Citrix Virtual Apps now offers the same capabilities as part of Citrix Virtual Apps and Desktops, the company's VDI offering.

A XenApp environment consisted of three parts:

A multiuser operating system. Microsoft Windows Server with the Remote Desktop Session Host feature allowed multiple users to independently access a server. Users could connect to individual Citrix XenApp applications or session-based desktops.
XenApp software. XenApp extended the Remote Desktop Services applications and desktops to client devices via the HDX protocol. HDX provides remote display capabilities, multimedia redirection, USB redirection and a variety of other capabilities, depending on the client device.
Client devices. Citrix XenApp applications and sessions could be accessed by endpoint devices using a software client called Citrix Receiver, which is now called the Citrix Workspace app. The software is available for a very large array of client form factors and operating systems.

Citrix XenApp versions

Beginning with the XenApp 7 release in 2018, XenApp was renamed Citrix Virtual Apps. Today, Citrix's virtualization product suites are Citrix Virtual Apps and Desktops (CVAD) -- which Citrix Virtual Apps is a component of -- and Citrix DaaS.

Previous Citrix XenApp versions went by the names MetaFrame, MetaFrame XP, MetaFrame Presentation Server and Presentation Server. MetaFrame hit the market in 1998. Its predecessor, WinFrame, debuted in 1995.

The product received the name XenApp following Citrix's acquisition of XenSource. Edition names included Citrix XenApp Fundamentals, XenApp Advanced, XenApp Enterprise and XenApp Platinum.

What does Citrix Virtual Apps do?

There are several different reasons organizations choose to deploy Citrix Virtual Apps, including the following:

Security. CVAD applications live in the data center, where IT can better protect them. Because the applications don't live on the endpoint, no data is at risk when a device is lost or stolen.
Support for remote and mobile workers. IT can centrally manage CVAD applications, even when workers are distributed.
PC refreshes and OS upgrades. Users can continue to access their CVAD applications as usual when they get new PCs or migrate OSes. Previously, IT had to reconfigure and redeploy the applications to each new or updated machine.