[pvnk]

FreeBSD isn't a Linux distribution. And yes it is different.

The first thing is the license, it gives the people that use your code much more freedom. I.e, it can be used in proprietary code and has been done, such as the whole TCP/IP stack in windows comes from FreeBSD. Yes, I'm not even close to being joking. BSD doesn't require people that modify your code to give you those changes as the GPLv3 does. Many differences in those two licenses. And in my opinion BSD license is much better.

The development process is different, GNU/Linux is an operating system that is built with the idea that it is good to develop the core system in individual groups. So, all of those packages that actually make up your system are developed by individual teams that don't actually have anything to do with each other. There isn't one team that oversees all of them or anything like that, GNU/Linux is an operating system that is just a collection of applications that are developed individually, everything from the core system. Now, Linus Torvalds said it at some Q&A that they have left numerous of bugs in the kernel they know about, but couldn't fix at the time because another application, such as glibc, took advantage of that bug. This is a flaw that shouldn't happen.

Linux is just the kernel, the user land is then developed in separate packages. While FreeBSD is the whole operating system. The FreeBSD project maintains and develops the whole system, from the kernel to the user land applications in the base system. This means that there is someone that maintains the whole system. Which leads to a better development process for everyone involved in the base system development and possibly fewer bugs such as the one I described earlier.

There are probably some other differences but mainly these two.

Really good read.