Parallels has unveiled Parallels Desktop for Mac 4.0, the next major version of the company’s virtualization platform for Intel-based Macs. The new version introduces over 50 features and enhancements, including the ability to run Leopard Server in a virtual machine.

Improvements in the new version include speed boosts that the company says are up to 50 per cent faster than the previous version of Parallels. In fact, making the application faster was one of the most requested features from its users and something the company focused a significant amount of time doing.

New features like the Adaptive Hypervisor allow Parallels to intelligently load balance the processes between the Mac OS and Virtual Machine. The virtualization engine itself has also been reworked to consume 15-30 percent less resources than it did before.

Graphics performance has been improved with added support for support for DirectX 9, DirectX Pixel Shader 2.0 and OpenGL 2.0.

Further improving the speed of Parallels, users can now dedicate eight CPUs and 8GB RAM to each virtual machine. Of course, the amount of resources that you can give to each virtual machine depends on the amount of physical resources you have available.

A new viewing mode called Modality allows users to set the transparency of the guest operating system, so you can view the activity of a virtual machine while in the background. Coherence has been updated as well. Now when you switch to Coherence, the Windows taskbar items move to the Mac’s menubar, so you always have access to them.

Virtual machines can now be started in Safe Mode. Everything will run exactly the same as it would if you started the machine normally except the changes you make while running in Safe Mode are not saved. This is handy if you are running beta software and something goes wrong. If everything worked okay, you do have the option of saving the changes when you stop the virtual machine and exit Safe Mode.

Parallels Desktop 4.0 for Mac is available immediately and costs £49.99. Current Parallels Desktop users can upgrade their existing software for £31.99. Users that purchased version 3.0 on or after September 1, 2008, qualify for a free upgrade to version 4.0.

Parallels is offering a special offer upgrade price until 30 November 2008 of £24.99.