CrossOver provides a framework, implementing Windows API calls, for these applications to run under non-Microsoft operating systems.
CrossOver is a retail product with the software available for digital download along with 12 months of e-mail support and upgrades and one phone support incident for $US 59.95. Additional support options may also be purchased.
Now, Linux users will undoubtedly be aware of the infamous WINE project which has long provided Windows application compatibility under Linux, and which is open source and freely available. In this case you might well ask what CrossOver can do for you that WINE cannot.
In fact, the CodeWeavers team are also the core developers of WINE. Purchasing CrossOver essentially funds the continued development of WINE.
CrossOver brings to the table a GUI for WINE along with facilities to receive custom WINE configurations that work best for many different Windows programs. In other words, rather than attempting to tweak and resolve compatibility issues yourself you can leverage the hard work the CodeWeavers team have gone to, to make many popular applications work as expected. Having trouble getting Adobe PhotoShop to work reliably, for example? Simply download the Photoshop WINE configuration through the CrossOver GUI.
You can search for yourself if the Windows titles you depend on will run under CrossOver through their compatibility database and you can also vote for support for Windows applications of your choice to receive attention and support. Popular titles at this time include Microsoft Outlook 2010, VMware vSphere Client, and Star Wars: The Old Republic.
To encourage participation in the democratic process, CodeWeavers has announced if they receive 100,000 pledges from eligible United States of America voters to vote in the 2012 Presidential Election they will make their software available for free over an entire day. This includes non-USA residents; all around the world may obtain the software that day. Existing customers will receive an additional 12 months support added to their account.