What is FreeBSD?
FreeBSD is an advanced operating system distributed under the 2-clause BSD license. The FreeBSD website has all the information needed (especially the handbook) to install and configure FreeBSD itself.
Building KDE SC trunk under FreeBSD
(The information on the pages linked here is obsolete in various ways) Please see the page on building KDE SC for general instructions. See the page on building KDE SC under FreeBSD for specific information for FreeBSD.