VMware has a new version of its desktop virtualisation software that makes colloboration between programmers easier and improves system simulations.

VMware Workstation 5 now has memory sharing technology borrowed from the company's ESX Server, plus a Teams feature that connects multiple virtual machines together in order to simulate and test higher-end applications on a programmer's desktop system.

The new version also allows desktop users to take "snapshots" of running virtual machines, and revert back to a previous snapshot with a single mouse click. Unlike the previous version, version 5 allows branching, and taking a snapshot does not obliterate changes made to previous versions of that VM.

Users can mark any virtual machine as a template, allowing multiple users to share its base installation, whether locally or across the network. Any changes made to the virtual machine are saved in a new virtual machine which reduces disk space and improves team collaboration, company officials claimed. Multiple VMs also save disk space by only storing changes between them.

"There are a lot more people building visor-based applications today, but building them is expensive because developers can't afford to buy machines for each and every developer. But with feature like Teams, for instance, allows developers to create multi-tier configurations on a single physical machine," said VMware product manager Srinivas Krishnamurti.

One developer said the new product's virtual capabilities have served to reduce their hardware costs. "We cut our costs by buying fewer PCs, and we can do more on one computer than we could with separate boxes. We can also isolate issues without having to worry about degradation of hardware or needing to rebuild systems," said Cognos quality control manager Cliff Thornton.

VMware 5 has added support for 64-bit operating systems and processors including Windows XP, Windows Server 2003 SP1, Red Hat Enterprise Linux 3 and 4, and SuSE Linux Enterprise Server. Support for chips with 64-bit extensions, such as AMD's Opteron and Athlon 64 and Intel's EM64T, are also supported.

The company has also added new 32-bit operating system support to the product for host and/or guest operating systems including Red Hat Enterprise Linux 4, Red Hat Linux Advanced Server 3, SuSE Linux Enterprise Server 9, SuSE Linux Pro 9.2, Mandrake Linux 10, Sun's Java Desktop System, and Novell's Linux Desktop 9.

VMware Workstation 5 works with both Windows and Linux host operating systems. The product can be downloaded for $189 through the VMware Store , or $199 for the boxed version.