Preliminary XML DTDs have been published through the Intuit Developer Network as part of Intuit's effort to open up its APIs to third-party developers. Intuit's QuickBooks Extensible Markup Language (qbXML) is a language "at the core of a new framework that allows electronic exchange, creation and management of accounting and other business data." Following the design maxim 'Never Enter Data Twice (NED2)', Intuit is constructing the XML specification for third-party applications to use to exchange data with QuickBooks. "With qbXML, software developers will be empowered to build specialized vertical applications and horizontal productivity applications that mine, enrich and share this data. Data integration will be supported with both Web applications and Windows desktop applications. A pre-release, open version of QuickBooks has been made available to participants in the QuickBooks SDK Beta program. The next major release of the US version of QuickBooks, QuickBooks 2002, will be accessible through the qbXML API, and is expected to be released in late fall 2001."