On Wednesday October, 31st, everybody can get a free copy of CrossOver with 12mths support.
CrossOver is an emulation layer for MacOS X and Linux. In contrast to virtualization solutions like VMWare, Parallels or VirtualBox, it allows running thousands of Windows applications, tools and games without having to install a legit Windows operating system.
All system functions and calls are translated in real time to their MacOS X or Linux equivalents. Codeweavers are contributing massivele to the open-source project Wine.
For a complete list of supported applications, tools and games, check here.