Explaining BSD

Greg Lehey

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Last modified on 2021-03-11 08:56:31 CET by root.

In the open source world, the word Linux is almost synonymous with Operating System, but it is not the only open source UNIX® operating system.

So what is the secret? Why is BSD not better known? This white paper addresses these and other questions.

Throughout this paper, differences between BSD and Linux will be noted like this.

Table of Contents
1. What is BSD?
2. What, a real UNIX®?
3. Why is BSD not better known?
4. Comparing BSD and Linux

1. What is BSD?

BSD stands for Berkeley Software Distribution. It is the name of distributions of source code from the University of California, Berkeley, which were originally extensions to AT&T's Research UNIX® operating system. Several open source operating system projects are based on a release of this source code known as 4.4BSD-Lite. In addition, they comprise a number of packages from other Open Source projects, including notably the GNU project. The overall operating system comprises:

  • The BSD kernel, which handles process scheduling, memory management, symmetric multi-processing (SMP), device drivers, etc.

  • The C library, the base API for the system.

    The BSD C library is based on code from Berkeley, not the GNU project.

  • Utilities such as shells, file utilities, compilers and linkers.

    Some of the utilities are derived from the GNU project, others are not.

  • The X Window system, which handles graphical display.

    The X Window system used in most versions of BSD is maintained by the X.Org project. FreeBSD allows the user to choose from a variety of desktop environments, such as Gnome, KDE, or Xfce; and lightweight window managers like Openbox, Fluxbox, or Awesome.

  • Many other programs and utilities.

All FreeBSD documents are available for download at https://download.freebsd.org/ftp/doc/

Questions that are not answered by the documentation may be sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.