4Suite allows users to take advantage of standard XML technologies rapidly and to develop and integrate Web-based applications. It also puts practical technologies for knowledge management projects in the hands of developers. It is implemented in Python and C. At the core of 4Suite is a library of integrated tools (including convenient command-line tools) for XML processing, implementing open technologies such as DOM, RDF, XSLT, XInclude, XPointer, XLink, XPath, XUpdate, RELAX NG, and XML/SGML Catalogs. Layered upon this is an XML and RDF data repository and server. The server supports multiple methods of data access, query, indexing, transformation, rich linking, and rules processing. It provides the data infrastructure of a full database management system, including transactions and concurrency support, access control and a variety of management tools. For purposes of integration with other tools, it supports remote, cross-platform and cross-language access through HTTP (including native SOAP and WebDAV), RPC, FTP and CORBA. It offers APIs in Python, HTTP, SOAP and XSLT.