Citrix is an American corporation that produces software designed to facilitate secure access to applications and content. Citrix offers products for Windows, Macintosh and Linux platforms. The company was founded in 1989 and currently has branches in several countries.
Citrix products include:
- Citrix Access Essentials
- Citrix Access Gateway
- Citrix Access Suite
- Citrix Application Gateway
- Citrix GoToAssist
- Citrix GoToMeeting
- Citrix GoToMyPC
- Citrix NetScaler
- Citrix Password Manager
- Citrix Presentation Server
Session virtualization and app virtualization with XenApp
Citrix XenApp is an on-demand virtual application delivery solution that comprises application virtualization and session virtualization technologies.
Understanding application virtualization
Citrix application virtualization technology isolates applications from the underlying operating system and from other applications to increase compatibility and manageability. As a modern application delivery solution, XenApp virtualizes applications via integrated application streaming and isolation technology. This application virtualization technology enables applications to be streamed from a centralized location into an isolation environment on the target device where they will execute. With XenApp, applications are not installed in the traditional sense. The application files, configuration, and settings are copied to the target device and the application execution at run time is controlled by the application virtualization layer. When executed, the application run time believes that it is interfacing directly with the operating system when, in fact, it is interfacing with a virtualization environment that proxies all requests to the operating system.
XenApp is unique in that it is a complete system for virtual application delivery, offering both online and offline application access through a combination of application hosting and application streaming directly to user devices. When users request an application, XenApp determines if their device is compatible and capable of running the application in question. The minimum requirements of a target device are a compatible Windows® operating system and appropriate Citrix client software. If the user device meets minimum requirements, then XenApp initiates application virtualization via application streaming directly into an isolated environment on the user’s device. In the event that the user device is not capable of running a particular application, XenApp initiates session virtualization.
Understanding session virtualization
Session virtualization uses application streaming to deliver applications to hosting servers in the datacenter. XenApp then connects the user to the server to which the application has been delivered. The application then executes entirely on the server. The user interacts with the application remotely by sending mouse-clicks and keystrokes to the server. The server then responds by sending screen updates back to the user’s device. Whereas application virtualization is limited to Windows-based operating systems, session virtualization via XenApp allows any user on any operating system to access any application delivered by IT. As a result, XenApp enables Windows, Mac, Linux, iOS and Android devices to run any applications using session virtualization. Furthermore, session virtualization leverages server-side processing power which liberates IT from the endless cycle of PC hardware refreshes which are typically needed to support application upgrades when using traditional application deployment methods.
Using application virtualization and session virtualization together
In both application virtualization and session virtualization, user interaction with the application is seamless. Printers, drives, peripherals, and even the clipboard work in the exact same manner as if the application were installed. As a result, XenApp reduces the cost of application management and related costs by up to 50 percent and enables a better-than-installed experience for users when compared to traditional application deployment models.
Citrix XenApp is a product that extends Microsoft Remote Desktop Session Host (formerly known as Terminal Services) desktop sessions and applications to users through the Citrix HDX protocol.
A XenApp environment consists of three parts:
- A multiuser operating system: Microsoft Windows Server with the Remote Desktop Session Host feature allows multiple users to independently access a server. Users can connect to individual Citrix XenApp applications or session-based desktops.
- XenApp software: XenApp extends 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 can be accessed by endpoint devices using a software client called Citrix Receiver. Receiver is available for a very large array of client form factors and operating systems.
Citrix XenApp versions
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 its current name in 2008, following Citrix’s acquisition of XenSource.
Today, there are multiple Citrix XenApp editions available, each with different features and prices. Edition names include Citrix XenApp Fundamentals, XenApp Advanced, XenApp Enterprise and XenApp Platinum.
What does Citrix XenApp do?
There are several different reasons organizations choose to deploy XenApp, including the following:
- Security: Citrix XenApp 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 Citrix XenApp applications, even when workers are distributed.
- PC refreshes and operating system upgrades: Users can continue to access their Citrix XenApp 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.