The Big Three Distros
http://www.netbsd.org/
http://www.freebsd.org/
What are the Differences Among the Three Versions?
Differentiating Among BSD Distros page 2 page 3 page 4
is an article at serverwatch that addresses this question. The article also considers Mac OS X. This article is set up to allow a link
into each section, so here is the contents of the article with links:
BSD History
Common Features
FreeBSD
NetBSD
OpenBSD
Mac OS X
Choosing a Desktop Solution
Choosing a Server Solution
A Few More Links
Google BSD
A bootable BSD CD is available at: http://www.freesbie.org/
http://www.bsdatwork.com/
http://www.linux-bsd-central.com/
http://www.bsd.org/
A Few of the Other Distros
http://www.386bsd.org/
http://www.dragonflybsd.org/main/
http://www.microbsd.net/
http://www.rofreesbie.org/