Hewlett-Packard is upgrading its virtualisation software offerings to help managers improve their data centres, while VMware is offering a virtualisation capability for web hosting companies.

HP this week announced enhancements to its HP Virtual Server Environment software for its Integrity line of servers, which creates a pool of virtual servers that can expand and contract depending on capacity needs.

HP also offers a specific software tool, Integrity Essentials Capacity Advisor, for easing the migration of data from Sun servers to HP servers.

HP's Integrity Essentials Global Workload Manager, another feature of Virtual Server Environment, specifies which computer workloads can automatically access available capacity in order to maintain service level agreements for key applications.

The company also announced a new Partner Virtualisation Program, which allows independent software vendors (ISVs) to test how their software will work with HP virtualisation.

Testing and fine-tuning can be done for virtualisation using HP ProLiant and Integrity servers, and with a number of operating systems, including HP-Unix, Windows Microsoft, and Novell and Red Hat Linux. The Virtual Server Environment also works with VMware virtualisation software.

Meanwhile, VMware announced the launch of its VMware Service Provider Program (VSPP), which allows web hosting services, telecommunications companies and other outsourcing businesses to include virtual infrastructure as a service offering.

Traditional hosting services use dedicated servers for each client, but virtualisation makes it possible to run multiple virtual servers, even for different clients, on one physical server. The web hosting company can then bill clients monthly, based on how many virtual machines they use, not physical ones, VMware said.