Citrix has announced a new release of its XenApp application virtualisation tool, adding Windows Server 2008 compatibility and speeding application performance for end-users. XenApp 5 also provides a common delivery method for both server-hosted applications and those running locally on client systems.

XenApp was previously known as Citrix Presentation Server until it was re-branded earlier this year, but version 5 is the first new release under this name. One of the key features is support for Windows Server 2008 (WS 2008).

"It's a fairly major release for us, because a lot of code had to be re-engineered for Microsoft's new platform," said Dave Austin, product marketing director for Citrix in EMEA.

XenApp on WS 2008 delivers "much better scalability" for enterprise-wide deployments, according to Austin, but he said Citrix has been careful to maintain backward compatibility so that firms can mix WS 2008 and WS 2003 deployments within the same server farm.

With XenApp, applications are packaged up and delivered from a XenApp Server to an isolated execution engine on the endpoint, rather than being installed within the local Windows environment in the conventional manner.

Now, XenApp can determine at login whether a user is on the network or outside the firewall, and what kind of device they are using. Policies set by the IT department can then determine whether the user gets an application streamed to their system for local execution, or is connected to the same application running in a server-hosted session.

"You can stream an application to a user with a laptop for offline use, for example, but if they are using an internet kiosk at the airport, you wouldn't want to have the application streamed to that device," said Austin. However, users will get the same experience whichever way the application is delivered, he added.

This kind of application virtualisation works well with virtual desktop environments such as Citrix' own XenDesktop. As applications can be delivered at login, it cuts the number of virtual machine images that need to be maintained.

Caching of some processes in XenApp 5 also means that users should see a faster login time, and applications should also start faster, according to Austin.

"For most users, this is important in improving their experience," he said.

XenApp 5 will be available from September 10. Pricing depends on region, but US licensing ranges from $350 (£190) to $600 (£326) per concurrent user.