From the project website (accessed 2016-01-12):
The Arches project is a collaboration between the Getty Conservation Institute (GCI) and World Monuments Fund (WMF) to develop for the international heritage field an open source, web- and geospatially based information system that is purpose-built to inventory and manage immovable cultural heritage. Arches incorporates widely adopted standards (for heritage inventories, heritage data, and information technology) so that it will offer a solid foundation that heritage institutions may customize to meet their particular needs. Arches is built using open source software tools to make its adoption cost effective, and to allow heritage institutions to pool resources to enhance Arches in mutually beneficial ways.
In June 2010, the GCI and WMF completed development of the Middle Eastern Geodatabase for Antiquities (MEGA)—Jordan, a web-based, Arabic-English geospatial information system built with open source tools and designed to serve as an archaeological site inventory and management system for the Jordanian Department of Antiquities (DoA).
The DoA deployed MEGA—Jordan kingdom-wide in December 2010. The DoA has allowed public access to the system for viewing and searching purposes at megajordan.org. However, to ensure security of the data, most of the advanced features of the system are not accessible to the public. The full functionality of the system may be viewed in an overview video on the megajordan.org homepage or on the MEGA-Jordan project pages. GCI-WMF have received numerous inquiries from heritage organizations around the world interested in potentially adopting MEGA, which has conveyed the broader need for such a tool. This interest led GCI-WMF to embark on the development of a generic information system for the international heritage field. Building on its experience with MEGA, in June 2011 GCI-WMF began to develop an open source, web- and geospatially based information system designed to inventory and manage all types of immovable heritage, including archaeological sites, buildings, structures, landscapes, and heritage ensembles or districts. The system is named "Arches." In order to lay the groundwork for developing Arches, and particularly to provide capability for documenting all heritage types (and not only archaeology as is the case of MEGA), GCI-WMF have undertaken extensive research on best practices and standards that are relevant to the development of a system of this type. The GCI and WMF consulted international best practices and standards, engaging nearly twenty national, regional, and local government heritage authorities from the United States, England, Belgium, France, and several Middle Eastern countries, as well as American and European information technology experts.During the development of version 1.0 of Arches, the contributions of heritage institutions played a critical role. Early on, the Flanders Heritage Agency gave test data and valuable advice on a number of development issues. English Heritage contributed substantially by providing additional data for system development, testing, and demonstration, by offering guidance on controlled vocabularies and the incorporation of the CIDOC CRM, and by leading the system documentation effort.