.XQL file extension

This is the basic program to work with .XQL extension

Altova XMLSpy

Altova XMLSpy XML Query Language

Altova XMLSpy is the industry’s best-selling XML editor and XML development environment for modeling, editing, transforming, and debugging XML technologies. In addition to the world’s leading XML editor, XMLSpy includes a powerful graphical XML Schema editor that allows you to design complex schemas with ease... (more)

The program works with the following extensions: xml, xq, fo, wml, xdr, xsd, xql, biz, tsd, mtx, tld, jsp, cml, dcd, xsl, ent, rdf, svg, spp, mml, vml, dtd, wsdl, xslt, rels, smil, math, vxml, xhtml and xquery

.XQL extension is also supported by the following programs:

XMLSPY 5 Enterprise Edition

XMLSPY 5 Enterprise Edition XML Query Language