In an apparent attempt to deliver a direct blow to VMware (current leader in the virtualization software market), Citrix has launched a new program that offers free support, training and conversion tools to customers that switch from using VMware hypervisors to using Citrix's XenServer or Microsoft's Hyper-V.

To receive the free benefits of Project Open Door - the new program's name - customers have to not only switch to a Citrix or a Microsoft virtualization platform but also purchase the Citrix Essentials set of management tools for either one of the two hypervisor products. The set includes storage integration, workload management, lifecycle management, dynamic provisioning and other tools.

While XenServer is free, the enterprise edition of the Essentials set is $2,750 and the platinum edition is $5,500. The latter edition differs from the former in that it includes provisioning services and automated lab management features.

VMware charges about $3,600 for vSphere 4 Enterprise (one processor with up to six cores) and about $4,370 for vSphere 4 Enterprise Plus (one processor with up to 12 cores). Both versions include patch and central management tools.

Customers have to decommission at least five vShpere 4 or VI3 servers and replace them with XenServer or Hyper-V to take advantage of the Project Open Door promotion, which will continue through March 2010.