So You Want to Write an Operating System

Yeah, so apparently if you're smart you don't write your own operating system. Although, if you do you do simple things like pick your audience, your goals, be God and the architecture you want. I liked the idea of Freedows and it was started by another young hacker (it seemed like it died because of personality clashes rather than technical although that probably helped).

http://www.osnews.com/story.php?news_id=1482

Yeah, yeah I'll finish it this month:
http://www.rcosjava.org/

Of course, using Java to teach operating systems is dumb, especially after you've done it already:
http://babylon.csua.berkeley.edu/

Anyway, real operating systems are written in assembly:
http://www.menuetos.org/