Oh, BTW.

Is Unix open source?

You have to be more specific. There are many OSes called UNIX. Some are open and some aren't. AIX, HP-UX, FreeBSD, SCO, NetBSD, OpenBSD, Solaris and many others. They probably all have programs in them that are open source. BIND and sendmail, namely, are in most or all of them and they are open, but the kernel and other programs in the specific UNIX distro may not be. You have to research the version of UNIX to find you answer.

okay. i didn't know that. so basically, it's like linux in that there are many distros, except w/ linux they're all open-source, right?

Well, almost. When you pick up a linux distro you expect the linux distro to be using the kernel, or some variation of it, that is maintained by Linus Torvalds (or whoever is maintaining an older kernel). With UNIX, they may all have different kernels. They probably all started in the same place but branched from eachother and have different code bases now.

I think you would benefit from reading this. It is the story of UNIX from Bell Labs. I enjoyed it when I first read it. You might want to read about the creation of Linux too. You can google for that I'm sure.

Thank you!

That's really helpful. That explains everything!

It also explains why so many organizations use it.