Citrix has released a new version of its free XenServer virtualisation platform, along with updated management tools for XenServer and Microsoft's Hyper-V technology.

XenServer 5.5, announced today at Citrix Synergy in Las Vegas, adds a number of new features, according to Citrix, including Active Directory integration for managing XenServer hosts and enhanced conversion tools to migrate virtual machines from one format to another.

It also expands support for guest operating systems to include newer releases of Suse Linux, Debian and Red Hat. The platform was made free to download in February, and the new release is available immediately from Citrix.

Also announced today was Citrix Essentials 5.5 for XenServer and Hyper-V, an update to the management tools introduced in February. It expands the product's StorageLink technology to work with a broader range of storage systems, and adds automated management for staging of servers and dynamic workload balancing, according to Citrix.

The latter enables administrators to set polices by which virtual machines can be automatically moved to another physical server using XenMotion if threshold conditions are triggered.

"As we seek to accelerate the rate of virtualisation adoption with the free XenServer product, we are also committed to providing the best advanced virtualisation management solutions for both XenServer and Hyper-V," said Peter Levine, senior vice president of Citrix's Virtualization Management Division.

Citrix Essentials 5.5 will be priced at $2,500 (£1,661) per server, the company said.

Citrix also unveiled a virtual implementation of its NetScaler web acceleration product that usually ships as a plug-in network appliance.

NetScaler VPX, set to be available for public preview from 18 May, can simply be downloaded and run on any standard server platform. Virtualising the tool opens up new ways of dynamically deploying it inside a datacentre, Citrix said.

It is expected to be commercially available in the third quarter of 2009.