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Nextstep - magazine - was created in 1995.
In Objective C NS means NextStep.
I haven't done it but check out this page on About.com, some past participants were interviewed:http://internships.about.com/od/internstories/a/felixnextstepconnectionsintern.htm
Windows 7 traces back to OS/2
OS X traces back to NeXTSTEP
The Mac OS X Kernel is a hybrid based on the XNU kernel derived from the former NextStep implementations. Much of the code is open source and freely available. (See links below)