XenApp is software developed by Citrix Systems Inc and is based on remote access and streaming technologies.
The current version of the XenApp product is XenApp 7.8 and is available as four different editions: starting with the XenApp Secure Browser Edition, followed by the entry level XenApp Advanced Edition, the XenApp Enterprise Edition and the premium XenApp Platinum Edition.
XenApp software facilitates access to a remote computer’s applications and/or it’s desktop display, allowing them to appear on another device (computer, smartphone, tablet) from where remote access is initiated.
XenApp simulates a remote computer’s application and desktop display and allows the user to interact with these. By taking the mouse movements and keyboard strokes made by the user on their computer and sending these to the XenApp software on the remote computer where the applications are located.
On the remote computer, XenApp applies the mouse movements and keyboard strokes to the applications or desktop and then sends any changes in the application or desktop appearance back to the user’s device. From where the XenApp client software, changes the screen appearance to match the actions of the keyboard strokes and mouse movements made.
To the user the application or desktop appears to be on their device when in reality the application or desktop is actually located and running on a remote computer.
Multiple users can connect to the same application or desktop on a remote computer at the same time and the XenApp software separates the individual access requirements and reduces any conflicts which may arise.
XenApp can provide access to individual applications (known as published applications) and to a simulation of the remote computer’s desktop screen (known as a published desktop).
Applications can also be streamed where they are packaged using special tools (Streaming Profiler) whereby the installation and configuration of the application is captured and stored in an application package.
The package is downloaded to the user’s computer (streamed) from where it can be launched. Without the need to install or configure the application on the user’s computer.
XenApp uses client software installed on a user’s computer to communicate with a XenApp computer which hosts (has applications installed on it) the applications used.
The Citrix Online Plug-in, acts as an intermediary, responsible for dealing with the images and sound sent from the remote XenApp computer. By presenting it on the user’s computer, so it looks like the application is working on the user’s computer when it is actually on the remote XenApp computer.
The client software also communicates with ports on the computer, such as the USB port. Allowing communication between devices attached to these ports and the application on the remote XenApp computer. So a USB memory stick will appear as though it is attached to the remote computer when it is really attached to the user’s computer.
The client software can also process information such as multimedia data (video and animations such as Adobe Flash based) on the user’s computer. Reducing the processing required on the remote computer.
This helps ensures the other users who are also using applications on the remote computer don’t end up suffering from resource hogging.
The Citrix offline plug-in is used for streamed applications and processes application packages downloaded. By creating an Application Isolation Environment (AIE) on the user’s computer, to where applications are streamed. Applications can then be launched from the AIE in isolation.
Citrix Receiver is installed on the user’s computer and acts as a repository. Providing management for various Citrix plug-ins including the online and offline plugins. The Receiver doesn’t itself provide remote access instead it’s the plug-ins stored within it, that do.
XenApp allows users to print from the applications they use to a printer attached to their computer or to which their computer has a network connection to.
As the application is not located on the user’s computer, XenApp sends the print information to the XenApp client software on user’s computer. This client software is responsible for sending the print information to the printer.
So a user using a word processing application running on a computer in London from their computer in New York. Would cause the XenApp server in London to send print information to their computer in New York.
Their computer in New York would send the printer information to the printer connected to their computer in New York or to a shared (network) printer in their New York office.
Flexcast Management Architecture
New versions of XenApp starting in the versions 7.x, use a different architecture to older versions. The new architecture is called Flexcast Management Architecture and replaces the existing Independent Management Architecture (IMA). See FMA vs IMA.
XenApp previous versions
XenApp 5.0, XenApp 6.0, XenApp 6.5
(XenDesktop 7.5 also provided a version known as App Edition but this has since been deprecated).