Since FreeBSD is developed as a complete operating system, user-installed applications are not considered to be part of the <quote>base</quote> system. User-installed applications are generally installed using <link xlink:href="@@URL_RELPREFIX@@/doc/en_US.ISO8859-1/books/handbook/ports-using.html">Packages or Ports</link>. In order to keep them separate from the base system, user-installed applications are installed under <filename>/usr/local/</filename>. Therefore, user-installed binaries reside in <filename>/usr/local/bin/</filename>, configuration files are in <filename>/usr/local/etc/</filename>, and so on.