Citrix XenApp was a remote access and application virtualization solution developed by Citrix Systems Inc. It allows users to access applications and desktop environments hosted on remote servers as though they were running locally on their devices. XenApp leverages Citrix’s streaming technologies to deliver these resources to end users.

Version

As of the latest update, XenApp 7.8 is the current version, available in four editions:

1. XenApp Secure Browser Edition
2. XenApp Advanced Edition
3. XenApp Enterprise Edition
4. XenApp Platinum Edition

These editions offer various features depending on the complexity and needs of the organization, ranging from basic browser access to fully integrated, high-performance virtual desktop solutions.

Remote Access

XenApp enables remote access to applications and desktop environments by streaming the display from a central server to an end user’s device. The software allows users to interact with these remotely hosted applications or desktops as if they were running locally.

• How it works: User interactions, such as mouse movements and keyboard inputs, are sent to the XenApp server hosting the application or desktop. The server processes these inputs and updates the screen accordingly, sending the updated visuals back to the user’s device. This creates a seamless experience where the application or desktop appears to be running on the user’s device when it is actually hosted on a remote server.

Multiple Users

One of XenApp’s strengths is its ability to support multiple users simultaneously on a single remote server. Users can access shared resources like applications or desktops concurrently, and XenApp efficiently manages these connections to minimize conflicts and ensure smooth performance for all users.

• XenApp supports published applications and published desktops. Published applications allow users to access specific programs, while published desktops provide access to a full desktop environment on the remote server.

Application Streaming

XenApp’s application streaming allows applications to be packaged using Citrix’s Streaming Profiler. Once packaged, these applications can be delivered to a user’s computer, where they are launched without the need for local installation or configuration.

• Streaming process: The application is stored in an isolated container on the user’s computer. This allows the user to run the app without affecting the local system, and the application can be used in an offline mode or streamed as needed.

Plugins and Citrix Receiver

Citrix Online Plug-in

XenApp uses the Citrix Online Plug-in, a client installed on the user’s computer, to communicate with the remote XenApp server. The plug-in acts as an intermediary, handling the graphics, audio, and other data sent between the user’s device and the remote XenApp server.

• The plug-in also facilitates communication between the user’s device ports (e.g., USB) and the remote application, enabling features like file access and printing from the local device.

Citrix Offline Plug-in

For streamed applications, the Citrix Offline Plug-in allows users to run downloaded application packages in an Application Isolation Environment (AIE). This environment keeps applications isolated from the user’s local system, reducing the risk of software conflicts.

Citrix Receiver

The Citrix Receiver is a software component that manages various plug-ins, including both the online and offline plug-ins. While Citrix Receiver does not provide remote access itself, it serves as a platform for the plug-ins that facilitate XenApp’s functionality.

Printing

XenApp allows users to print from remote applications to printers connected to their local devices or networked printers. For example, a user working on a remote server in one city can print documents to a printer in a different location by leveraging the XenApp client on their local device, which manages the communication between the application and the printer.

FlexCast Management Architecture (FMA)

Starting with XenApp version 7.x, Citrix introduced the FlexCast Management Architecture (FMA), replacing the older Independent Management Architecture (IMA). FMA offers a more streamlined and scalable infrastructure for managing virtual applications and desktops across an enterprise environment. The switch to FMA allows for better integration with newer Citrix products, such as XenDesktop.

XenApp Previous Versions

Earlier versions of XenApp include:

• XenApp 5.0
• XenApp 6.0
• XenApp 6.5

Older versions of XenApp, particularly those using the Independent Management Architecture (IMA), have since been phased out in favor of FMA, which is now the standard architecture.

Key Features of XenApp

• Remote Access: Provides users access to applications and desktops hosted on remote servers.
• Multi-User Support: Allows multiple users to connect to the same server and use applications concurrently.
• Application Streaming: Applications can be streamed to users without installation, saving time and resources.
• Client and Receiver Integration: Facilitates seamless communication between the user’s device and remote servers, including printing and peripheral support.
• High Security: Centralized data storage ensures that sensitive information is not stored on user devices, providing a secure environment for businesses and users.
• FMA Architecture: Ensures scalability and simplified management for enterprise-level deployments.

Conclusion

Citrix XenApp is a versatile and powerful tool for delivering remote applications and desktops to users, ensuring secure and efficient access across multiple devices. With features like application streaming, multi-user support, and high-security protocols, XenApp continues to be a cornerstone in the virtualization and remote access space for businesses of all sizes. The transition to the FlexCast Management Architecture further enhances its capabilities, making it more adaptable for modern IT infrastructures.