Overview of Citrix and Virtualization Technology

Citrix Systems (www.citrix.com) is a leading provider of technology for virtualization of applications and servers. The company was formed in 1989 and its name is a portmanteau of Citrus (the original name of the company) and UNIX. It had over $1 Billion in revenue in 2009 and employs over 4800 worldwide. Citrix is headquartered in Fort Lauderdale, Florida.

Andreas Krebs authored an excellent brief overview of Citrix technology in the All Covered Learning Center:

In 1995, Citrix introduced the world to virtualization with NT 3.5 WinFrame, an application virtualization solution.  Later, they offered NT 4.0 Terminal Server, a desktop virtualization solution.  As the founders of virtualization technology, Citrix is the company that many businesses recognize and trust for their virtualization solutions.

Server Virtualization
XenServer is Citrix’s no-cost server virtualization solution that gives small and medium sized businesses an affordable and effective way to adopt an enterprise-class technology.  Unlike other server virtualization solutions, XenServer provides premium grade features for free.  Benefits include the following:

• XenServer supports an unlimited number of servers, virtual machines and physical memory.
• XenServer includes a conversion function will allow you to convert a virtual server into a physical server and physical server into a virtual server as needed.  (Other server virtualization solutions will charge you for this feature.)
• Shared SAN and NAS storage between server hosts maximize available storage on the network.
• All virtualized servers can be accessed and maintained from a single location.
• In the event of server failure, affected virtual machines are automatically restarted on other production servers.
• A library of pre-configured virtual machine templates make it easy to rapidly create a test or production environment.
• Centralized patch management makes it easy to keep virtual servers updated.
• Easy migration of virtual systems to from one host server to another makes it simple to maintain host servers.
• XenServer is open-source and takes advantage of the intellectual contributions of thousands of users, hundreds of companies and partners.
• XenServer is compatible with most server hardware that is currently available.

Desktop Virtualization
XenDesktop is Citrix’s desktop virtualization solution.  As an on-demand service, XenDesktop will deliver a Windows desktop to any user, anywhere.  Features include the following:

• XenDesktop users can access their desktop and corporate applications from any PC, Mac, thin client or smart phone.
• XenDesktop gives users a computing experience that rivals a local PC, even when using Multimedia, 3D graphics or VoIP-integrated applications.
• Each desktop is customizable to meet the performance and security needs of individual users.
• XenDesktop will work with your existing hypervisor, storage and Microsoft infrastructures—you don’t have to spend more money buying compatible programs.

Application Virtualization
XenApp is Citrix’s application virtualization solution that allows users to directly access Windows applications from through a desktop computer or web browser.  Benefits include the following:

• Windows applications can be accessed on devices that have non-Windows based operating systems—more than thirty operating systems are currently supported.
• This solution requires that only one virtualized copy of an application such as Office 2010 be installed and maintained, while allowing any number of users to access and use it as if it was locally installed.
• Applications can be streamed directly from the host server for users working on the corporate network or remotely.  Permissions can even be set up to allow users to download and access apps while offline.
• Virtualized applications function as if they are locally installed.
• Application delivery and access is customizable for each user and their preferred device, network and typical access location.

Virtualization Management
Essentials for XenServer is an add-on enhancement that complements XenServer by providing additional features and integrated management capabilities for server, desktop and application virtualization.

• One-click access to native storage makes device management simple.
• Automated high-availability protection will move virtualized machines from a failed host server to another physical server.
• Automated management of lab infrastructures decreases the complexity, time and cost of managing non-production environments.
• Automated workload balancing will move virtual servers to hosts with more available resources based on pre-configured policies.

There are many use cases for Citrix virtualization, including the standardization of desktops, the delivery of legacy applications, enhanced security, being able to deliver a uniform user experience on a variety of different platforms, and others. These all enable lower total cost of ownership and other benefits to the organizations that deploy virtualization technologies.

This post is a very brief overview of Citrix and virtualization technology. The Citrix website is an excellent place to learn more about this important technology.

Thanks for reading.