Initially, the software was released as 'Parallels Workstation for Mac OS X', consistent with the Linux and Windows versions. This was not well received within the Mac community, where some felt that the name, particularly the term “workstation,” evoked the aesthetics of a Windows product. Parallels agreed: “Since we've got a great Mac product, we should make it look and sound like a Mac product...”, it was therefore renamed ‘Parallels Desktop for Mac’.
Parallels Desktop for Mac is a hardware emulation virtualization software, using hypervisor technology that works by mapping the host computer’s hardware resources directly to the virtual machine’s resources, allowing each virtual machine to operate identically to a standalone computer. Each virtual machine effectively has its own processor, RAM, floppy and CD drives, I/O devices, and hard disk, essentially all the resources of a physical computer. Parallels Desktop for Mac virtualizes all devices within the virtual environment, including the video adapter, network adapter, and hard disk adapters. It also provides pass-through drivers for parallel port and USB devices.
Because all guest virtual machines use the same hardware drivers irrespective of the actual hardware on the host computer, virtual machine instances are highly portable between computers. For example, a running virtual machine can be stopped, copied to another physical computer, and restarted.
Parallels Desktop for Mac is able to virtualize a full set of standard PC hardware, including
Version 2.5 brought support for USB 2.0 devices, which expanded the number of USB devices supported at native speed, including support for built in iSight USB web-cams. The amount of video RAM allocated to the guest OS was made adjustable, up to 32MB. Full featured CD/DVD drives arrived in this version, which allowed the user to burn disks directly in the virtual environment, and play any copy-protected CD or DVD as one would in OS X. In addition, a shared clipboard and drag-drop support between OS X and the guest OS was implemented. This version brought the ability for users with a Windows XP installation to upgrade to Windows Vista from within the VM environment. A new feature known as Coherence was added, which removed the Windows chrome, desktop, and the virtualization frames to create a more seamless desktop environment between Windows and OS X applications. This version also allowed users to boot their existing Boot Camp Windows XP partitions, which eliminated the need to have multiple Windows installations on their Mac. A tool called Parallels Transporter was included to allow users to migrate their Windows PC, or existing VMware or Virtual PC VMs to Parallels Desktop for Mac.
In 2007, Netsys sued Parallels' German distributor Avanquest for copyright violation, claiming that Parallels Desktop and Parallels Workstation are directly based on a line of products called "twoOStwo" that Parallels developed on paid commission for Netsys, of which it says, Netsys has been assigned all copyrights, according to news sources. The lawsuit claimed that Parallels Desktop 2.5's compatibility with "twoOStwo", which was developed for and paid for by Netsys, showed that the two software products are run by essentially the same functional core. When Netsys lost its initial urgency proceeding, in which it requested a temporary injunction from the Landgericht district court of Berlin, it filed a new suit.
Version 3.0 retained all of the functionality from previous versions and added new features and tools. Support for DirectX 8.1 and OpenGL was added, allowing Mac users to play some Windows games without the need to boot into Windows with Boot Camp. A new feature called SmartSelect offers cross OS file and application integration by allowing the user to open Windows files with Mac OS X programs and vice versa. Parallels Explorer was introduced, which allows the user to browse their Windows system files in OS X without actually launching Windows. A new snapshot feature was included, allowing one to restore their virtual machine environment to a previous state in case of issues. Further, Parallels added a security manager to limit the amount of interaction between the Windows and OS X installations. This version included a long awaited complete "Parallels tools'" driver suite for Linux guest operating systems. Therefore integration between Mac OS X and Linux guest-OS's has been greatly improved.
Despite the addition of numerous new features, tools and added functionality, the first iteration of Desktop for Mac 3.0 may be missing some of features that Parallels had planned for it. A Parallels, Inc. representative stated at MacWorld in January 2007 that version 3.0 would bring accelerated graphics, "multi-core virtual machines/virtual SMP, some SCSI support, a more Mac-like feel, as well as a more sophisticated coherence mode, dubbed Coherence 2.0". While accelerated graphics have materialised, Coherence, as well as the overall look and feel of Parallels Desktop for Mac has only changed slightly. Also, SCSI support has not been implemented.
It is currently unknown if these features have been abandoned altogether, or if they will show up in a later build of version 3.0.
Build 4560, released on 2007-07-17, added an imaging tool which allowed users to add capacity to their virtual disks.
Build 5160, released on 2007-09-11, added some new features and updated some current features.
The release focused on updates to Coherence, with support for Exposé , window shadows, and transparent windows and the ability to overlap several Windows and Mac windows. Further, Parallels' Image Tool was updated to allow one to change their virtual hard disk format between plain and expanding. Parallels Explorer was updated to allow for one to automatically mount an offline VM hard drive to the Mac desktop. Some new features added are iPhone support in Windows, allowing iTunes in Windows to sync with it. Users can now mirror desktops or other folders. Further, Mac drives can now be mapped by Windows and sound devices can now be changed 'on the fly'. Up to 2 GB of RAM can be allocated to a virtual machine, with a total of 4 GB of RAM available.
Parallels Desktop for Mac Build 5608 is now available for download This build adds support for guest Parallels Tools for Linux in the latest Linux distributions (including Ubuntu 8). It also includes added support for running 3D graphics in your Windows VM on Mac OS X Leopard 10.5.3.
Originally, Parallels Desktop did not support Windows Vista Home Basic or Windows Vista Home Premium, because Microsoft's license for these operating systems prohibits their use with a virtual machine. However, because Microsoft has dropped its restrictions on running these operating systems in virtualized environments, Parallels Desktop now supports Windows Vista Home and Windows Vista Home Premium.