Operating Systems Through Time (8-bits) A brief history of 8-bit operating systems. http://www.armory.com/~spectre/tech.html

In the Beginning was the Command Line A history of operating systems, by Neal Stephenson. http://www.cryptonomicon.com/beginning.html

History of the AmigaOS GUI Dedicated to the preservation and restoration of the Amiga Workbench's history. http://www.gregdonner.org/workbench/

Operating Systems History A Brief History of Computer Operating Systems from the mid 1950s on. http://www.cs.gordon.edu/courses/cs322/lectures/history.html

OldOs.org -- Your site for computing fun, old and new Since 2001, Old Os has been the #1 source for utilities, history, and everything you need to get your old computer up and running, either in emulation or in real life. http://www.oldos.org

easysoft Operating systems are defined here. All type of operating systems like windows,unix,linux,debian are defined here.open bsd as well as bsd is described here http://www.easysoft.tk

Tools For Thought by Howard Rheingold. Online copy of well known 1985 book on the invention of computing; includes Babbage, Turing, von Neumann, Engelbart, PARC, Kay, and Atari. http://www.rheingold.com/texts/tft/