A protocol based on Extensible Markup Language (XML) and intended for instant messaging (IM) and online presence detection. It functions between or among servers, and facilitates near-real-time operation. 

The use of a textual syntax to represent MPEG-4 3-D scene descriptions. XMT was designed to provide content authors the ability to exchange their content with other authors while preserving their intentions in the text format. 

An open Extensible Markup Language (XML)-based protocol that specifies a way to establish and manage a universal addressing system. An XNS universal address serves as a permanent contact point for an individual or other legal entity.

A project devoted to the creation of a system for open source network routing. XORP is available without cost. It is script-able and can be used as a production router or a network emulator. It can easily be adapted to VoIP, e-commerce and OLTP.

A language that describes a way to locate and process items in Extensible Markup Language (XML) documents by using an addressing syntax based on a path through the document's logical structure or hierarchy. 

An attack targeting Web sites that create XPath queries from user-supplied data. If an application embeds unprotected data into an XPath query, the query can be altered so that it is no longer parsed in the manner originally intended. 

A way to locate and filter the elements (data fields) and text in an Extensible Markup Language (XML) document. XQL provides a tool for finding and/or selecting out specific items in the data collection in an XML file or set of files. 

A proposed standard digital rights management (DRM) markup language. The XML-based language enables users to specify rights and conditions associated with resources, such as digital content or Web services. 

A Recommendation of the World Wide Web Consortium (W3C), that specifies how to formally describe the elements in an Extensible Markup Language (XML) document.

A language for creating a style sheet that describes how data sent over the Web using the XML is to be presented to the user. It describes exactly which data fields in an XML file to display and exactly where and how to display them. 

A standard way to describe how to transform (change) the structure of an XML (Extensible Markup Language) document into an XML document with a different structure. 

xtimeline is a newly released service that lets you create a timeline on a subject of your choice, and allow others to contribute to it as well.

XtremIO is an all-flash scale-out enterprise storage cluster design that provides substantial improvement in I/O performance. XtremIO arrays are created using building blocks called "X-Bricks" that are high-availability, high-performance, fully active/active storage system with no single point of failure.

A derivative of the Ubuntu operating system, using the Xfce desktop environment. It provides an easy to use distribution, using Xfce as the graphical desktop, with a focus on integration, usability, performance, and low memory footprint.

A standard way to exchange data that describes a program's user interface, or at least the portion of it that can be controlled by programming. 

xUnit is a free, open source, community-focused unit testing tool for the .NET Framework. It can be used for C#, F#, VB.NET and other .NET languages.  It is compatible and works with ReSharper, CodeRush, TestDriven.NET and Xamarin.