* FreeBSD (based on 4.4BSD-Lite)
    * PicoBSD
    * TnyBSD
    * NanoBSD
    * MiniBSD
    * DragonFlyBSD (a FreeBSD 4.X variant)
    * TrustedBSD
    * PCBSD
    * Midnight BSD
    * DesktopBSD

  * OpenBSD
    * MirOS (an OpenBSD variant)

  * NetBSD

----
Reference
  * [[http://www.serverwatch.com/tutorials/article.php/3393051 | Differentiating Among BSD Distros]]
  * [[http://www.serverwatch.com/tutorials/article.php/3565016 | Beyond The Big Three BSDs, BSD Alternatives ]]