Empweb is an open and extensible framework for building library circulation systems.

In Empweb, transactions, like loans, renewals and reservations, are handled by a customizable \\\'\\\'transaction pipeline\\\'\\\', constructed from a sequence of reusable rules. This makes transactions extensible and modular, allowing the creation of custom rules, written in Java or even in scripting languages.

Empweb is based on the following principles:

• Customizable transaction rules.
• Customizable library policies with extensible and dynamic set of limits.
• Multiple local and remote databases for objects and users.
• Multi-language and internationalization.
• Multi-platform: written in Java and tested in Linux and Windows.
• A layered and distributed architecture.
• Documented protocols, exchange formats and APIs.
• Standards compliant: MODS, CDS/Isis, Xisis, XML, SOAP, XHTML, CSS.

In this re lease, the traditional EMP format (TRPLIV, TRPUSU) is used to store transactions. Other non-transactional data, like calendars and profiles, are stored in an Xisis database. An abstraction layer allows to plug in other implementations of the database back-end.

A standards compliant and extensible web interface is also provided. This interface has been carefully built to be accessible from any computer capable of running a browser (graphical or console), considerably lowering costs.

This framework can empower libraries by allowing them to leverage their existing technologies while freeing them from the dependence on closed architectures.