

| Acronym | Sense | Language | Topics | 
|---|---|---|---|
| UDP | User Datagram Protocol | In English | |
| UDP/IP | User datagram protocol/Internet Protocol | In English | → Internet | 
| UDWDM | Ultra Dense Wavelength Division Multiplexing | In English | → Telecommunications | 
| UGC | User Generated Content | In English | → Computer-based techniques | 
| UMVF | Université Médicale Virtuelle Francophone (www.umvf.prd.fr) | In French | → Higher education, universities → Medicine → Internet → France | 
| UNE | Unbundled Network Elements | In English | → Telecommunications | 
| URI | Uniform Resource Identifier | In English | → Libraries | 
| URL | Uniform Resource Locator | In English | |
| VAX | Virtual Address Extended | In English | |
| VC-ATOD | Virtual Clearinghouse on Alcohol, Tobacco, and Other Drugs = CV-ATOD | Centro Virtual de Información sobre Alcohol, Tabaco y otras Drogas | In Spanish | In English | → Libraries → 6635 → 6639 → Pathology | 
| VDSL | Very High Speed Digital Subscriber Line | In English | |
| VEB | Virtuala Esperanto-Biblioteko | In Esperanto | → Libraries → Internet → Artificial languages (linguistics) | 
| VEKI | Virtuala Esperanto Kongreso Internacia | In Esperanto | → Congresses → Artificial languages (linguistics) | 
| VHDSL | Very High Speed Digital Subscriber Line | In English | |
| VHDSL | Very High-speed Digital Subscriber Line | In English | → Telecommunications | 
| VIP | Virtual Instance Port | In English | → Telecommunications | 
| VITE | Vienna IT Enterprises | In English | → Telecommunications | 
| VLSM | Variable Length Subnet Masking | In English | |
| VMTP | Versatile Message Transaction Protocol | In English | |
| VoIP | Voice over Internet Protocol | In English | → Telecommunications | 
| VPN | Virtual Private Network = RPV | Réseau Privé Virtuel | In French = RPV | Red Privada Virtual | In Spanish = SPN | Skynprivaatnetwerk | In Afrikaans = VPN | Virtueel Particulier Netwerk | In Dutch = VPN | Virtuellt Privat Nätverk | In Swedish | In English | |
| VPN | Virtueel Particulier Netwerk = RPV, SPN (look above) | In Dutch | |
| VPN | Virtuellt Privat Nätverk = RPV, SPN (look above) | In Swedish | |
| VSN | Video Switching Network | In English | |
| W3C | World Wide Web Consortium | In English | → Organizations and associations | 
| WACM | Web Application Configuration Manager | In English | → Internet | 
| WACT | Web Application Component Toolkit | In French | → Software | 
| WAE | Wireless Application Environment | In English | → Software | 
| WAE | Web Application Extension | In English | → Software → Internet | 
| WAFC | Web Application Firewall Criteria | In English | → Internet | 
| WAI | Web Accessibility Initiative | In English | → Internet → Telecommunications | 
| WAM | Web Application Manager | In English | → Software → Internet | 
| WAM | Web Access Management | In English | → Management → Internet | 
| WAN | Wide Area Network | In English | |
| WAP | Wireless Access Protocol | In English | → Telecommunications | 
| WASP | Wireless Application Service Providing | In English | → Software | 
| WASP | Web Analytics Solution Profiler | In English | → Software → Internet | 
| WASP | Web Application Structure for PHP 5 | In English | → Software → Internet | 
| WBAN | Wireless Body Area Network | In English | → Internet → Medicine | 
| WBI | Web Browser Intelligence | In English | → Software → Internet | 
| WBS | Word Based Search (www.wbs.org) | In English | → Internet → Linguistics → Dictionaries | 
| WCCP | Web Cache Control Protocol | In English | → Internet | 
| WCDMA | Wideband Code Division Multiple Access | In English | → Telecommunications | 
| WCM | Web Content Management | In English | → Internet → Document processing → Knowledge management | 
| WDM | Wavelength Division Multiplexing | In English | → Telecommunications | 
| WDP | Wireless Datagram Protocol | In English | |
| WDVL | Web Developer's Virtual Library (www.wdvl.com) | In English | → Software → Internet | 
| WebDAV | Web-based Distributed Authoring and Versioning | In English | → Document processing | 
| WECA | Wireless Ethernet Compatibility Alliance | In English | → Organizations and associations | 
| WEP | Wired Equivalent Privacy | In English | |
| WFQ | Weighted Fair Queueing | In English | |
| WFQ | Weighted Fair Queuing | In English | |
| WHATWG | Web Hypertext Application Technology Working Group (www.whatwg.org) | In English | → Organizations and associations → Software → Internet | 
| WIEU | Women's International Electronic University | In English | → Higher education, universities | 
| WIM | WAP Identification Module | In English | → Internet → Telecommunications | 
| WIM | WAP Identity Module | In English | → Internet → Telecommunications | 
| WLL | Wireless Local Loop | In English | |
| WMAN | Wireless Metropolitan Area Network | In English | → Telecommunications | 
| WML | Wireless Markup Language | In English | → Software → Internet → Telecommunications | 
| WML | Website Meta Language | In English | → Software → Internet | 
| WMLS | Wireless Markup Language Script | In English | → Computer science → Internet → Telecommunications | 
| WMS | Web Management System | In English | → Software → Internet | 
| WOS | Web Operating System | In English | → Operating systems → Internet | 
| WPAD | Web Proxy Autodiscovery Protocol | In English | → Internet | 
| WPAN | Wireless Personal Area Network | In English | |
| WPAN | Wireless Personal-Area Network | In English | → Telecommunications | 
| WPS | Web Positioning System | In French | |
| WS-CDL | Web Services Choreography Description Language | In English | → Programming languages → Internet | 
| WS-I | Web Services Interoperability | In English | → Telecommunications | 
| WSCI | Web Services Choreography Interface | In English | |
| WSCL | Web Services Conversation Language | In English | → Programming languages | 
| WSDL | Web Service Description Language | In English | → Software | 
| WSDL | Web Services Description Language | In English | → Internet | 
| WSFL | Web Services Flow Language | In English | → Programming languages | 
| WSMO | Web Service Modeling Ontology | In English | → Data → Programming languages → Internet → Semiotics | 
| WSN | Wireless Sensor Network | In English | → Telecommunications | 
| WSOA | Web Services Oriented Architecture | In English | → Software | 
| WSP | Wireless Session Protocol | In English | |
| WSP | Web Standard Project | In English | → Internet | 
| WSRP | Web Services for Remote Portlets | In English | → Internet | 
| WSVM | Web Site Verification Mechanism | In English | → Internet | 
| WTLS | Wireless Transport Layer Security | In English | |
| WTP | Wireless Transaction Protocol | In English | |
| WWW | World Wide Web = TTT | Tut-Tera Teksaĵo | In Esperanto | In English | → Internet | 
| XBEL | XML Bookmark Exchange Language | In English | → Programming languages → Libraries | 
| XBL | Exploits Block List | In English | → Software → Computer infections | 
| XDM | XPath Data Model | In English | → Data | 
| XEP | XMPP Extension Proposal | In English | → Telecommunications | 
| XFN | XHTML (EXtensible HyperText Markup Language) Friends Network | In English | → Programming languages → Data" | 
| XHR | XMLHttpRequest | In English | → Software → Internet | 
| XHTML-MP | Extensible Hypertext Markup Language - Mobile Profile | In English | → Telecommunications | 
| XINS | XML Interface for Network Services | In English | |
| XMPP | EXtensible Messaging and Presence Protocol | In English | |
| XSS | Cross-Site Scripting Attack | In English | |
| СЦИ | Синхронная Цифровая Иерархия = SDH | Synchronous Digital Hierarchy | In English = SDH | Synchrone Digitale Hiërarchie | In Dutch = SDH | Synchrone Digitale Hierarchie | In German = SDH | Szinkron Digitális Hierarchia | In Hungarian = SDH | Synkron Digital Hierarki | In Swedish | In Russian |