Non Viral Open Source XQuery Written In Java

Almost a year ago I asked "Anyone out there knows about a non-viral open source XQuery implementation?". See, back then every open source java implementation was GPL'ed.

Fortunately, my wishes have come true and ObjectWeb has announced a new XQuery implementation called XQuark! Better yet there are several other implementations that I didn't see before, that is Saxon and Rainbow.

• XQuark Bridge - XQuark Bridge expands existing relational database functionalities with advanced XML import/export capabilities. Using a powerful mapping language, it can perform efficient insertion of structured XML data into existing relational tables, while taking into account the database integrity constraints and transforming the implicit relations appearing in the XML document into explicit ones in the database. It also supports flexible extraction and publishing of relational data into any target XML format, using the XQuery language. (LGPL)
• Saxon - The latest installment of the implementation has support for XQuery 1.0. This version reflects the syntax of the Working Drafts of 22 August 2003. (Mozilla Public License)
• Rainbow- XQuery Processing system using relational technology. RainbowCore is an XQuery processing engine using XQuery decorrelation, rewriting and optimization techniques and a unified general-purpose XML Query Algebra named XAT (XML Algebra Tree), serving as a solid yet scalable foundation for extended XML-based applications. (Qt Public License)

Interesting, Jason Hunter (Servlet book fame) is again in position to exploit this new technology. He owns www.xquery.com and with Mike Clark (JDepend fame) released a test suite called Bumblebee. My fearless forecast is that XQuery is going to be the standard for enterprise data access in a couple of years.