Internet Infrastructure

BSD has existed since the last 1970's and was the testbed and reference implementation for TCP/IP.
The Internet Software Consortium (ISC) uses FreeBSD exclusively for f-root domain servers (in 21 cities now, usually with 3 servers per city).
Modern FreeBSD is extremely refined and mature.
FreeBSD consistently placed at the top of the "uptime" lists produced by Netcraft to measure the stability of the world's busiest websites.

BSD has existed since the last 1970's and was the testbed and reference implementation for TCP/IP.