Similar to Speech_Synthesis_Markup_Language
 - W3C Markup Validation ServiceW3C Markup Validation Service
 - Template:W3C標準Template:W3C standards
 - Web Accessibility InitiativeWeb Accessibility Initiative
 - Web Open Font FormatWeb Open Font Format
 - WebAssemblyWebAssembly
 - WebAuthnWebAuthn
 - XLinkXLink
 - XML Information Set
 - XML Path LanguageXPath
 - XML基底XML Base
 - XML情報集合
 - XPath
 - XPointerXPointer
 - XQueryXQuery
 - XSL
 - ウェブストレージWeb storage
 - SPARQLSPARQL
- 文字参照Character entity reference