Available immediately, Desktop 5 for Mac adds numerous improvements that address performance and make it easier to get up and running with a virtual machine.
These include full support for the Aero features in Windows 7 and Vista through a Windows Display Driver Model, and improved performance for Linux virtual machines through KVM para-virtualisation.
"We are head and shoulders above our rivals with this new release," said Perry Warner, Apple channel manager for Parallels in UK and Nordic countries.
Crystal mode is the major new feature, according to Warner, as it makes Windows "almost invisible in the background".
As well as making Windows applications appear to be running on the Mac desktop, Desktop 5 for Mac also now enables them to have a look and feel more in keeping with OS X.
Called MacLook, this feature puts Mac buttons on window borders, Mac-style dialogue boxes and even Mac-style icons on the Windows desktop, if the user chooses to see it.
Apple shortcuts have also been mapped to Windows applications, so that users can copy by hitting Apple-C, just as they would in a native application.
Performance has been beefed up, with 3D graphics performance in Desktop 5 up to seven times faster than the previous release, thanks to OpenGL 2.1 and support for the VT-X technology in Intel's Nehalem processors, according to Warner.
In Crystal mode, the Windows virtual machine will also be suspended if there are no active processes running, releasing system resources back to native Mac applications until the user needs to use a Windows application.
The Parallels Compressor is also incorporated into this release and automatically optimises the virtual machine, reducing its footprint on the disk.
For corporate users of Desktop for Mac, version 5 adds the ability for an administrator to lock down virtual machines so that a password is required to stop users making changes or creating new ones.
Desktop 5 for Mac also has support for the latest Snow Leopard release of Mac OS X, and supports up to eight virtual processors and 64-bit versions of Windows.
Users who bought version 4.0 on or after 1 October 2009 will be eligible for a free upgrade, Parallels said, which must be claimed before 15 January 2010.