The Complete FreeBSD, 4th Edition

FreeBSD is by far the most popular version of BSD, the legendary operating system that has contributed a great deal to every version of Unix® in use today (including Mac OS X). Originally a community effort by the University of California at Berkeley, FreeBSD was aimed at making Unix a little friendlier and easier to use. By the time other free operating systems came along, BSD was firmly established and very reliable. And it continues to be today.