FreeBSD is an open-source operating system and UNIX derivative. The OS is compatible with x86 systems (including Pentium and Athlon), AMD64 systems (including Opteron, Athlon64, and EM64T), UltraSPARC -, IA-64, PC-98, and ARM architectures.

FreeBSD supports most of the common PC hardware: USB 2.0, Bluetooth, PCMCIA, SCSI and S-ATA RAID controller. However, some drivers are not provided by the hardware manufacturer, but rather are written by FreeBSD developers themselves. There is an implementation of Windows NDIS interface can be used on the Windows driver for NICs.

The FreeBSD kernel provides support for stateful IP firewalling, as well as IP proxy gateways, access control lists, mandatory access control, jail-based virtual hosting and cryptographically secure data storage.

More features

* Support for IPsec and IPv6
* Supports Notebook Docking stations, which are controlled via ACPI
* Filesystem Unionfs
* Extensible kernel security of the TrustedBSD MAC Framework
* Supported network protocols 802 1q VLANs, PPP, L2TP
* TrustedBSD audit
* GEOM-based disk encryption (GBDE)
* Supported network hardware (Gigabit Ethernet, WLAN, ATM, ISDN, FDDI)
* X.org 7.3
* GNOME 2.26
* KDE 4.2.2
* BIND 9.3.4-p1
* Sendmail 8.14.2

Conclusion
FreeBSD is a stable operating system that is popular with Internet providers mainly due to its ruggedness.