FreeBSD是一份UNIX操作系统，它面向i386、IA-64、PC-98、 Alpha/AXP及UltraSPARC平台。它基于加州伯克利大学的4.4 BSD-Lite发布，并带有一些4.4 BSD-Lite2增强。它还非直接地基于William Jolitz的port，这源于加州伯克利大学i386化的“Net/2”也即“386BSD”，尽管386BSD中只有非常少的代码遗留下来。 FreeBSD被遍布全世界的公司、Internet服务提供商、研究人员、计算机专家、学生，以及家庭用户用于他们的工作、教学和娱乐之中。

FreeBSD 6.3 has been released: "TheFreeBSD Release Engineering Team is pleased to announce theavailability of FreeBSD 6.3. This release continues the development ofthe 6-STABLE branch providing performance and stability improvements,many bug fixes and new features. Some of the highlights: KDE updated to3.5.8, GNOME updated to 2.20.1, X.Org updated to 7.3; BIND updated to9.3.4; Sendmail updated to 8.14.2; lagg driver ported from OpenBSD /NetBSD; Unionfs file system re-implemented; freebsd-update now supportsan upgrade command. FreeBSD 6.3 is dedicated to the memory of Dr.Junichiro Hagino for his visionary work on the IPv6 protocol and hismany other contributions to the Internet and BSD communities." Read the release announcement and release notes for further information. Download: 6.3-RELEASE-i386-disc1.iso (625MB, MD5), 6.3-RELEASE-amd64-disc1.iso (673MB, MD5). Also available via BitTorrent.