Wikimedia
Wikipedia: Ms Dos
Wikipedia gives an excellent definition of Microsoft's original disk operating system, MS-DOS, including hyperlinked terms and more.
Other
Dos Tutorial
Ever wanted some simple explanations of MS-DOS systems? This site gives them to you in a question and answer format.
Computer Hope
Computer Hope: Information on Batch Files
This site from Computer Hope.com contains information and help with DOS batch files.
A&E Television
Biography: Paul Allen
Biography.com offers a three-page biography of entrepreneur and investor Paul Allen.