The Boost web site provides free peer-reviewed portable C++ source
libraries.  The emphasis is on libraries which work well with the C++
Standard Library.  One goal is to establish "existing practice" and
provide reference implementations so that the Boost libraries are
suitable for eventual standardization.  Some of the libraries have
already been proposed for inclusion in the C++ Standards Committee's
upcoming C++ Standard Library Technical Report.

This slave port forces the use of GCC 3.4+ and is intended for FreeBSD 4.x
only (in fact, it's IGNOREd on later FreeBSD versions).

So, if you port needs GCC 3.4+ and Boost, or it needs spirit 1.8, that is
not available with GCC 2.95.4, you can use this port as a dependency.

WWW:  http://www.boost.org/