From Parallels, Inc.:

Parallels Workstation is the most powerful, easiest-to-use, cost-effective desktop virtualization solution available today. It empowers any user, from experienced professional developers to computer \"newbies\", to create completely networked, totally secure independent, maximally stable virtual machines on a single physical machine without partitioning or rebooting. Virtual machines can run nearly any x86 operating system, including the entire Windows family from 3.1 - XP/2003/Vista, Linux, FreeBSD, OS/2, eComStation, Sun Solaris and MS-DOS. Using the product’s easy step-by-step wizard, users can create virtual machines in seconds. Users can also easily manage active or inactive virtual machine properties with zero training by using Workstation’s e intuitive, web-like interface. The product is available at an industry-leading price of $49.99/license.