...
For now, build notes can be found in the BuildingShibboleth topic.
The above site is now offering as-yet-unreleased OpenSAML 2 library requires at least version 1.3.1 , with version 1.3 becoming available in August 2006...Note that version 1.3, required by OpenSAML 2 (C++ Edition), is not yet of this library, which is officially released, but will be at some point. The code is publically available in the Apache svn trunk:
http://svn.apache.org/repos/asf/xml/security/trunk/c
%COMMENT%contains some known bugs that affect some signature verification scenarios. The final release of OpenSAML 2.0 will probably require a newer xml-security version, possibly a 1.4.