Chapter 2. About Evergreen

Evergreen is an open source library automation software designed to mee the needs of the very smallest to the very largest libraries and consortia. Through its staff interface, it facilitates the management, cataloging,and circulation of library materials, and through its online public access interface it helps patrons find those materials.

The Evergreen software is freely licensed under the  GNU
General Public License,
meaning that it is free to download, use, view, modify, and share. It has an
active development and user community, as well as several companies offering
migration, support, hosting, and development services.
The community's development requirements state that Evergreen must be:

Evergreen, which first launch in 2006 now powers over 544 libraries of every type-public, academic, special, school, and even tribal and home libraries - in over a dozen countries worldwide.