XML -Extensible Markup Language
XSS -Cross-Site Scripting
XAML -Extensible Application Markup Language
XSD -XML Schema Definition
XHTML -Extensible Hypertext Markup Language
XPATH -XML Path Language
XSL -Extensible Stylesheet Language
XSLT -Extensible Stylesheet Language Transformations
XPS -XML Paper Specification
XPI -Cross-Platform Installer
XMPP -Extensible Messaging And Presence Protocol
XEN -Xen Hypervisor
XSERVER -X Server
XCLIENT -X Client
XORG -X.Org Foundation
X86 -Extended 86 Architecture
X64 -64-bit Extension Of X86 Architecture
X-AXIS -Horizontal Axis
XBOX -Microsoft Xbox Console
XDR -External Data Representation
XENAPP -Citrix XenApp
XENMOTION -Xen Motion
XPG -X/Open Portability Guide
XMS -Extended Memory Specification
XDR MEMORY -Extreme Data Rate Memory
XGA -Extended Graphics Array
XINPUT -Xbox Input API
XPCOM -Cross Platform Component Object Model
XWD -X Window Dump
XBM -X Bitmap
XCF -EXperimental Computing Facility
XMI -XML Metadata Interchange
XPS VIEWER -XML Paper Specification Viewer
XTERM -X Terminal Emulator
X509 -Extended Public Key Infrastructure Standard
XNS -Xerox Network Systems
X11 -X Window System Version 11
XFT -X FreeType Interface Library
XFER -Transfer
XDCAM -Extended Digital Camera
XQUERY -XML Query Language
XPC -Cross-Platform Component
XNS PROTOCOL -Xerox Network System Protocol
XRC -XML Resource File
XUL -XML User Interface Language
XINPUT HID -Xbox Human Interface Device
XDF -Extended Density Format
XPG4 -X/Open Portability Guide Version 4
XCB -X C Binding
XSL-FO -Extensible Stylesheet Language Formatting Objects