Noun
(computer science) software that controls the execution of computer programs and may provide various services
Source: WordNetThe best way to prepare to be a programmer is to write programs, and to study great programs that other people have written. In my case, I went to the garbage cans at the Computer Science Center and fished out listings of their operating system. Bill Gates
No one cares what operating system you run as long as it stays up. Bruce Perens
By the time Apple's Macintosh operating system finally falls into the public domain, there will be no machine that could possibly run it. The term of copyright for software is effectively unlimited. Lawrence Lessig
I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones. Linus Torvalds
I started Linux as a desktop operating system. And it's the only area where Linux hasn't completely taken over. That just annoys the hell out of me. Linus Torvalds
Any type of operating system that I wanted to be able to hack, I basically compromised the source code, copied it over to the university because I didn't have enough space on my 200 megabyte hard drive. Kevin Mitnick