Story

Here are a couple of starting points. I'm not a zealot: I use both Linux and FreeBSD and like them for different reasons. The BSDs tend to be more conservative, so instead of systemd you've still got init scripts; it boots more slowly, has less hardware support, so on. The Linux distros evolve more rapidly, but they also sometimes stray into territory (HAL, Udev) that turn out to be a mistake.The absolute classic resource on the question is here, though it's a couple years out of date now.: https://www.over-yonder.net/~fullermd/rants/bsd4linux/01https://www.freebsd.org/doc/en/articles/explaining-bsd/comparing-bsd-and-linux.html

BSD projects maintain the entire "Operating System", not only the kernel. This distinction is only marginally useful: neither BSD nor Linux is useful without applications. The applications used under BSD are frequently the same as the applications used under Linux.As a result of the formalized maintenance of a single CVS source tree, BSD development is clear, and it is possible to access any version of the system by release number or by date. CVS also allows incremental updates to the system: for example, the FreeBSD repository is updated about 100 times a day. Most of these changes are small.

This one seems pretty good: http://www.techrepublic.com/blog/10-things/10-differences-between-linux-and-bsd/

There is an old saying about BSD vs. Linux: "BSD is what you get when a bunch of Unix hackers sit down to try to port a Unix system to the PC. Linux is what you get when a bunch of PC hackers sit down and try to write a Unix system for the PC.

Finally, this quote from Nesbitt http://www.nesbitt.ca/freebsd.html agrees with me:

The FreeBSD documentation is available as a constantly updated, well written web handbook (and on paper as well). The handbook covers each and every aspect of the FreeBSD system in a concise, yet thorough, style. The documentation manages the delicate balance of being both a definitive resource for an experienced administrator, and a valuable learning guide for a Unix neophyte. It is written in a style that does not presuppose much familiarity with Unix systems, and covers such basic Unix topics as permissions, but also covers advanced topics such as kernel configuration and tuning, security and encrypted disk partitions.

I find Linux distros have wildly varying approaches to documentation, and I frequently turn first to Google searches. The FreeBSD is far more authoritative, and because the ports packages and kernel/base system are all maintained together as one integral source tree, everything fits together and seems to me to be more professionally managed. Somehow, and it's hard to describe exactly, everything seems more cohesive. But the documentation is a big deal. It's very easy to get instructions from the source on how to do exotic things like set up a PPP server or a SLIP connection, and beyond. That's useful on some systems, but on others you want Linux for hardware compatibility and faster boot times.