The software is currently maintained solely at the largesse of the Shibboleth Consortium, which has subsidized all development time on this project for many years. It would likely be unsupported at present if not for that project.
The Apache XML Security for C++ package makes heavy use of the Xalan-C and Xerces-C++ libraries from the Apache Software Foundation.
This product includes cryptographic software written by Eric Young (firstname.lastname@example.org). This product includes software written by Tim Hudson (email@example.com).
This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit.
The license documents for Xerces, Xalan and OpenSSL are contained in the doc directory in SVN and in the doc directory in distributions of the C++ source code.