Server consolidation is likely to become easier with the integration of VMware's hypervisor technology into servers from Dell, Fujitsu-Siemens, HP and IBM. The move was announced at the VMworld Europe expo, where the company also detailed forthcoming security features and improvements in its virtual desktop infrastructure to help firms scale up deployments and let workers use virtual desktops offline.

VMware said its ESX 3i hypervisor will be embedded into servers available from the four vendors with 60 days. Buyers of these systems will also have access to an evaluation of VMware's broader Virtual Infrastructure 3 (VI3) suite, which can provide a fully managed virtual datacentre, the company said.

The hypervisor is a compact 32MB in size and sits beneath the level of any operating system. Integrating it with the physical server makes it easier for customers to support virtual servers without having to install and manage a host operating system.

"Because it is embedded, customers can rapidly deploy virtualisation – you can just plug a new server in and switch it on to integrate it with your virtual datacentre," said VMware senior marketing manager Martin Niemer.

Analysts said that the move is one VMware had to make to defend its market share against Microsoft, which will release it its Hyper-V virtualisation software later this year.

"Anyone buying a server with Windows Server 2008 will be able to get virtualisation built in when Hyper-V ships," said Roy Illsley of Butler Group.

Gartner's Phil Dawson said the real battleground will be in the medium-size enterprise market. "VMware is already well entrenched in the datacentre, and this is about defend their business and attacking new markets." He added that the deciding factor is likely to be which vendor can provide the best tools for administrators to manage workloads.

Fujitsu Siemens said its Primergy servers factory-fitted with the hypervisor are available immediately, while HP is to offer it on 10 models of ProLiant server shipping from the end of March and all virtualisation-certified Dell PowerEdge servers will have it from early April.

Experts have been raising concerns about security in virtual environments for some time, and VMware said future versions of its Virtual Infrastructure will provide hooks for third-party security vendors to tap into. Called VMsafe, this will provide the same level of oversight into virtual machine operation as the hypervisor. Vendors such as CheckPoint, McAfee and Symantec have already pledged support.

"If you run a virus scanner inside a virtual machine, a virus can potentially stop it," said Niemer. He said that VMsafe will be a 'new way of approaching security'.

VMware also detailed forthcoming tools to make virtual desktops more attractive to enterprises, including Scalable Virtual Image technology to deploy and manage large numbers of virtual images, and Offline Virtual Desktop Infrastructure to allow laptop users to keep a virtual desktop on their machine synchronised with a server-based copy in the office.