There are a lot ways to serve applications to end users working from PCs and other devices, and Citrix Systems thinks it has come up with the right combination of options: mix everything together and let companies and end users decide.
With XenDesktop 4, announced Monday, Citrix is adding 70 new features to its virtual desktop infrastructure (VDI) server, which allows a server hypervisor - not just XenServer, but also Hyper-V from Microsoft or ESX Server from VMware - to serve up virtual Windows or Linux PC slices over the corporate network.
With VDI, so long as you have a network link, you have a PC, which is great but also limiting for mobile users who often want to work even when they don't have a network. Ditto for feeding server-based applications to end users over the network, which has been done using Presentation Server (now called XenApp) for years.
This places a lot of load on the central servers and the networks linking in to run the applications back in the data center, but that is the price you pay to have centralized control of applications and data.
But with the mix of XenDesktop and XenApp, and the integration of the future Project Independence XenClient bare metal hypervisor for PCs that Citrix and Intel are cooking up for vPro-compatible PCs, Citrix now says it will be able to deliver local PC images in virtual machines as well as remote ones through VDI and also allow applications to be streamed down from central servers and run either remotely or locally, depending on how customers want it.
The term that Citrix wants us to use for this is "flexcasting," and it runs the gamut. It includes the local VM-based desktops with operating systems and applications that can be run offline (in XenClient, due for delivery sometime in the first half of 2010), as well as virtual applications installed on desktops and local applications streamed down to desktops, which in all cases use the local computing power, graphics cards, web cams, and peripherals of the local device.
On the server side, the Citrix XenDesktop software stack will support hosted blade PC desktops - with a one-to-one ratio - hosted PCs on shared servers - VDI through what used to be called XenDesktop - and hosted shared desktops - using XenApp.
The stack also includes the VM-hosted applications, a feature that debuted in mid-September with XenApp 5 Feature Pack 2. This allows a single legacy Windows application to be wrapped up in a virtual machine and streamed down to PC users without having to make any code changes - as XenApp often requires. This hosted VM approach, which mixes XenApp and XenDesktop features, was a precursor to the merged XenDesktop and XenApp announced today.
By the way, the merger of the XenDesktop and XenApp functionality with the new XenDesktop 4 has one other important change: the way it is priced. XenDesktop 4 is priced based on named users, but the standalone XenDesktop and XenApp are both priced based on concurrent users.
This may not seem like a big deal, but at many companies, there are many different work shifts and the number of named users far exceeds the number of concurrent users. Ditto for service providers, who often stream applications using XenApp. And for this reason, the company will continue to sell XenApp as a standalone product according to the vice president of Citrix's XenDesktop product group Sumit Dhawan.
Dhawan says that Citrix thinks that 2010 is going to be the year when companies really start thinking about virtualization, VDI, and application streaming, and this goes from being a pilot project to becoming a production desktop environment. Citrix certainly needs this to be true, since it shelled out $500m two years ago to acquire XenSource, the company behind the open source Xen hypervisor.