...The software, also called Evergreen, is used by libraries to provide their public catalog interface as well as to manage back-of-house operations such as circulation (checkouts and check-ins), acquisition of library materials, and (particularly in the case of Evergreen) sharing resources among groups of libraries. Evergreen depends on the following technologies Perl, C, JavaScript, XML, XPath, XSLT, XMPP, OpenSRF, Apache, mod_perl, and PostgreSQL. The latest stable release of a supported Linux distribution is recommended for an Evergreen installation.