FreeBSD is a free Unix-based operating system descended from AT&T UNIX via BSD UNIX.
FreeBSD® is an advanced operating system for modern server, desktop, and embedded computer platforms. FreeBSD's code base has undergone over thirty years of continuous development, improvement, and optimization. It is developed and maintained by a large team of individuals. FreeBSD provides advanced networking, impressive security features, and world class performance and is used by some of the world's busiest web sites and most pervasive embedded networking and storage devices.