XML has spawned a growing family of related technologies -- so many in fact, that even the most ardent W3C observer is bound to forget what a few of those X-related acronyms stand for. Keep this chart in your bookmark list, and you'll always have the answer to "what X stands for" right at your fingertips.

gXML

Guideline XML, a file structure for exchange of electronic-commerce guidelines in an XML data format.

SVG

Scalable Vector Graphics -- a scalable vector graphic format based on XML.

XBL

Extensible Binding Language -- a markup language that describes bindings for XUL files.

XHTML

Extensible Hypertext Markup Language -- a hybrid markup language resulting from combining XML 1.0 and HTML 4.0.

XLink

XML Linking Language (also known as XLL) -- contains the rules for adding hyperlinks to XML documents.

XLL

XML Linking Language (also referred to as XLink) -- contains the rules for adding hyperlinks to XML documents.

XMI

XML Metadata Interchange Format, a standard of the OMG

XML

Extensible markup language -- An open standard for defining data elements on a web page.

XML-RPC

Remote Procedure Calls with XML

XPath

Rules for addressing internal elements in an XML document.

XPointer

Rules for linking to internal structures in an XML document.

XQL

Extensible Query Language -- for addressing and filtering the elements and text of XML documents.

XSIL

Extensible Scientific Interchange Language -- a flexible, hierarchical, transport language for scientific projects.

XSL

Extensible Stylesheet Language -- A stylesheet format for XML documents.

XSLT

Extensible Stylesheet Language Transformations -- language used to reconstruct/transform the structure XML documents.

XUL

Extensible User-Interface Language -- toolbox for creating the user interface for a cross-platform application.