| Extension |
Information |
| U |
Subsampled Raw YUV Bitmap |
| U |
Unreal Tournament 2003 System File (Epic Games, Inc.) |
| U |
Nitpicker Ipflow File |
| U |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| U |
Unreal System File |
| U2 |
Telelogic Tau UML Model |
| U2E |
Unreal Game Translation |
| U2P |
Telelogic Tau UML Program Text File |
| U3D |
Universal 3D File |
| U3P |
U3 Platform Install File (U3 LLC.) |
| U4A |
UnInstaller Archive |
| U8 |
Raw Unsigned 8-Bit Audio Data |
| U96 |
EasyZip Temporary File |
| U98 |
Urdu 98 Document |
| UAE |
WinUAE 0.8.22 Game Configuration File |
| UAP |
User Agent Wireless Telephony Profile |
| UAS |
PhotoImpact Backup/Recovery File (Ulead Systems, Inc.) |
| UAX |
Unreal Tournament 2003 Sound (Epic Games, Inc.) |
| UAX |
Deus Ex |
| UAX |
Harry Potter |
| UAX |
Rune |
| UAX |
Unreal / Unreal 2 |
| UAX |
Unified Application eXchange Format (UAX Project) |
| UAX |
Undying |
| UAX |
Unreal Audio File (Epic Games, Inc.) |
| UB |
Raw Unsigned Byte (8-bit) Data |
| UB |
Audio |
| UBB |
BASIC UBAS File |
| UBD |
BASIC UBAS File |
| UBK |
National Construction Estimator 32 User Costbook |
| UBK |
Embiid Reader eBook (Embiid Inc.) |
| UBM |
Iphoto Mtwain Install File |
| UBS |
Tracesrv Bugslayer Utility File |
| UC |
AutoCut Flash Firmware File (Autometrix) |
| UC |
Unreal Tournament Code File (Epic Games, Inc.) |
| UC2 |
UltraCompressor II Compressed Archive (AIPNL) |
| UCD |
Prosa/ OM Use Case Diagram |
| UCE |
UniCode Extensions |
| UCF |
Xilinx Foundation User Constraint File |
| UCF |
Epson Personal Settings Information (Epson Corporation) |
| UCG |
ULEAD MediaStudio CG Infinity Graphic (Ulead Systems,
Inc.) |
| UCM |
Urban Chaos Game File |
| UCMN |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UCN |
Compressed Archive |
| UCN |
U-Act Configurator Configuration Storage File (Unisys) |
| UCR |
MicroSim PCBoard Unrouted Nets Report |
| UCS |
Homeworld Localized Unicode Strings (Sierra Entertainment,
Inc.) |
| UCS |
Universal Classification Standard Database File |
| UCX |
Rational XDE (IBM) |
| UD |
OmniPage User Dictionary (ScanSoft, Inc.) |
| UD |
AOL 4.0 (America Online, Inc.) |
| UDB |
PINO 3-Server File |
| UDB |
Windows2000 Uniqueness Database File (Microsoft) |
| UDB |
Works File (Microsoft) |
| UDC |
Acrobat Spelling File (Adobe) |
| UDC |
Systems Management Server (SMS) Collection Evaluator
Updates Collection (Microsoft Corporation) |
| UDC |
Fh5 US English File |
| UDD |
OllyDbg Module Information (Oleh Yuschuk) |
| UDF |
Excel User Defined Function (Microsoft) |
| UDF |
Windows NT Uniqueness Database File |
| UDF |
Photostyler Image Filter |
| UDF |
X-ray Diffraction Data File Format |
| UDI |
Dazzle DVD Complete (Pinnacle Systems, Inc.) |
| UDI |
Corel Graphics Ver 10 Draw Script Textures Bitmap File
(Corel) |
| UDL |
ADONIS User Export From Database (BOC Group) |
| UDL |
Data Link (Microsoft) |
| UDM |
MapView User-Defined Module (MotCreations) |
| UDS |
Sierra Generations Geneology Family File (Sierra
Entertainment, Inc.) |
| UDS |
FIMware Database (Uniform Data System for Medical
Rehabilitation, a division of UB Foundation Activities, Inc.) |
| UDW |
Raw Unsigned DoubleWord (32-bit) Data |
| UE2 |
Encrypted Archive |
| UEF |
Unified Emulator Format |
| UEZ |
COOL 3D (Ulead Systems, Inc.) |
| UFA |
GIF Animator Animation Object Information (Ulead) |
| UFA |
UFA Compressed File Archive |
| UFF |
DataWave Physiological Data File |
| UFI |
UFOCaptureV2 Presets (SonotaCo) |
| UFO |
Ellisys Visual USB Data (Ellisys) |
| UFO |
PhotoImpact Graphic (Ulead Systems, Inc.) |
| UFO |
Total Annihilation Third-party Unit (Cavedog
Entertainment) |
| UFSD |
UFS Explorer Professional Recovery RAW Recovery Signatures
Database (SysDevSoftware) |
| UG |
Drawing File |
| UGA |
Ulead GIF Animator Project File (Ulead) |
| UH |
Age of Kings (Microsoft) |
| UHA |
UHARC Compressed Archive |
| UHS |
Universal Hint System File (Universal Hint System) |
| UHTM |
Unreal Tournament File |
| UI |
User Interface |
| UI |
Geoworks UI Compiler Espire Source |
| UID |
IBM Voice Type Users File (IBM) |
| UIF |
WordPerfect Long Prompts (Corel Corporation) |
| UIF |
Magic ISO Universal Image Format File (MagicISO Inc.) |
| UIH |
Geoworks UI Compiler Espire Header |
| UIL |
X-Motif UIL Table |
| UIN |
ICQ 2001+ Saved ICQ Contact Information (ICQ Inc.) |
| UIR |
LabWindows User Interface Resource (National Instruments
Corporation) |
| UIS |
WindowBlinds Skin |
| UKA |
UKA Data Archive (HRM Systems AG, CH-Winterthur) |
| UKA |
Fifa World Cup Game Data fe Art Legalscr File |
| UKS |
Works File (Microsoft) |
| UKX |
Unreal Tournament 2003 Animation (Epic Games, Inc.) |
| UK_ |
Mcguiness File |
| UL |
uLAW Audio File |
| ULD |
Procomm Uploaded Files |
| ULF |
Uniware Layout File (Uniware) |
| ULP |
EAGLE Layout Editor Script (CadSoft Computer GmbH) |
| ULP |
Peugeot Diag 2000 File |
| ULS |
Internet Location Service |
| ULT |
UltraTracker Music Module |
| ULW |
ULAW - Sun/NeXT |
| ULX |
CLAN Lexical File (Child Language Data Exchange System) |
| ULX |
Glulx Game |
| UM |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UM |
The Land Of UM World File |
| UMB |
MemMaker Backup Archive |
| UMD |
UMD Photobook |
| UMI |
CDDB Database and PC Music Library in PlayCenter |
| UML |
Visual UML Class Diagram & Model (Visual Object
Modelers, Inc.) |
| UMOD |
Unreal Tournament (Epic Games, Inc.) |
| UMOD |
Unreal Self-extracting MOD File (Epic Games) |
| UMS |
Rune |
| UMX |
Harry Potter |
| UMX |
Unreal/Unreal Tournament Music File (Epic Games, Inc.) |
| UMX |
U-MYX Player Song Mix Data and Timing Info (U-MYX Ltd.) |
| UMX |
Unreal Tournament 2003 Music (Epic Games, Inc.) |
| UMX |
Deus Ex |
| UNASSIGNED |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UNCIAL |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UND |
A86 Assembler Undefined Symbols |
| UNF |
Btreive Unformatted File |
| UNI |
Forcast Pro Data File |
| UNI |
MikMod (UniMod) Format |
| UNION |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UNIVERSAL3 |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UNIX |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UNIX |
UNIX File |
| UNKNOWN |
[None] |
| UNL |
Informix Binary File Created by UNLOAD Command |
| UNLOCK |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UNM |
XMap Flight Plan or Flight Plan Statistic File (Delorme) |
| UNPAC |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UNPACK |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UNQ |
ACT! Saved Unknown Attachment (Best Software CRM Division) |
| UNQ |
Fax View File |
| UNR |
Unreal Map File |
| UNS |
Visual Navigation Suite Export/Import Settings (Jeppesen
Marine, Inc.) |
| UNT |
AutoCAD Unit Definition (Autodesk, Inc.) |
| UNUSED |
Photoline4 Defaults File |
| UNV |
Forecast Pro Univariate Forecast File (Business Forecast
Systems, Inc.) |
| UNV |
BusinessObjects/WebIntelligence Universe File |
| UNV |
SDRC I-DEAS File |
| UNX |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UNX |
Text File |
| UN_ |
Ntgraph Setup30 file |
| UOL |
PhotoImpact Object Library File |
| UP |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UP2 |
Cool3d Plug-ins Board File |
| UPC |
Ultimate Paint (J-T-L Development Inc.) |
| UPCASE |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UPD |
Updated Program Data |
| UPD |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UPD |
dBASE Update File |
| UPD |
ProUpdater Per/Directory Options Setting File |
| UPD |
VideoStudio Scene Information (Ulead Systems, Inc.) |
| UPD |
Universal Print Driver |
| UPDATE |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UPDATE |
ISAPI Loader New ISAPI Application (EGGcentric) |
| UPDATE |
Program or Data File Update |
| UPDATEALL |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UPDATEINFO |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UPDATES |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UPDF |
UltraPdf Publication (Software995) |
| UPF |
Nokia Phone Digital Photo (Nokia) |
| UPF |
Universal Picture Format Bitmap |
| UPG |
Firmware Upgrade File |
| UPG |
Grafik Anim File |
| UPI |
Iphoto4 Programs Plug-in File |
| UPI |
ULead Photo Impact Program File |
| UPJ |
ULead Project File |
| UPL |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UPL |
Starmoney Agent Download File |
| UPM |
PenMail Document (UC-Logic Technology Corp.) |
| UPO |
dBASE Compiled Update File |
| UPR |
FileMaker User Spelling Dictionary |
| UPS |
Works File (Microsoft) |
| UPT |
Connectivity Memory Model Update Timing Input File |
| UPX |
ULead Photo Express Saved Image File |
| UPZ |
Starmoney Agent Download File |
| UQM |
The Ur-Quan Masters Archive (The Ur-Quan Masters Team) |
| URBS |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| URD |
Ultra Recall Database (Kinook Software, Inc.) |
| URD-JOURNAL |
Ultra Recall Journal Update File (Kinook Software, Inc.) |
| URF |
ProWORX Nxt User Configurable Register Editor File
(Schneider Electric) |
| URF |
Radar ViewPoint Universal Radar Format |
| URF |
AppFace Skin (Matinsoft Inc.) |
| URI |
List of Uniform Resource Identifiers |
| URIS |
List of Uniform Resource Identifiers |
| URL |
Internet Location |
| URLS |
GetRight URL List (Headlight Software, Inc.) |
| URS |
ControlDraw User Requirements Specifier (ControlDraw Ltd.) |
| URT |
Utah Raster Image |
| US |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| USA |
Unreal Saved Game File |
| USA |
Office Header File (Microsoft) |
| USAGE |
Snort File |
| USAGE |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| USB |
Syssoft Sandra File |
| USB |
USB Protocol Analyzer Trace |
| USB |
D-Link FM Radio Update |
| USE |
Log File |
| USE |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| USE |
MKS Source Integrity File |
| USER |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| USERPROFILE |
Live Update User Profile (Symantec) |
| USF |
Core Media Player XML Universal Subtitle Format File
(CoreCodec, Inc.) |
| USF |
Nintendo Ultra 64 Sound Format (Nintendo) |
| USI |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| USI |
UsiXML UI Description File (Universite Catholique de
Louvain-la-Neuve) |
| USL |
ProWORX Nxt USL Loadables (Schneider Electric) |
| USL |
LaserJet Landscape Font |
| USL |
PC-Bibliothek User Dictionary (Bibliographisches Institut
& F.A. Brockhaus AG) |
| USP |
SIMCA-P/SIMCA-P+ Project (Umetrics AB) |
| USP |
PageMaker Printer Font (Adobe) |
| USP |
LaserJet Portrait Font |
| USR |
ERGO Receiver Configuration File (Creative Express
Corporation) |
| USR |
User Database |
| USR |
MicroImages User-specific Information (MicroImages, Inc.) |
| USR |
Uplink Player Information File (Introversion Software) |
| USR |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| USR |
Photo Paint User Defined Filter (Corel) |
| USR |
Pegasus Mail User Information (David Harris) |
| USR |
FileMaker Pro Runtime Engine Database Application
(FileMaker, Inc.) |
| USS |
PhotoImpact Exported Slicing Pattern (Ulead Systems, Inc.) |
| USS |
WinUAE Saved State |
| UST |
WiFi SiStr Exported User Theme (DNsoft.be) |
| USTAR |
POSIX tar Compressed Archive |
| USX |
Unreal Tournament 2003 Static Mesh (Epic Games, Inc.) |
| USYM |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| USZ |
UsiXML UI Description File (Universite Catholique de
Louvain-la-Neuve) |
| UT2 |
Unreal Tournament Map (Epic Games, Inc.) |
| UT2MOD |
Unreal Tournament 2003 Game Modification File (Epic Games) |
| UT4MOD |
Unreal Tournament 2004 MOD Installation Package (Epic
Games) |
| UTC |
BioWare Aurora Engine Creature (BioWare Corp.) |
| UTD |
BioWare Aurora Engine Doors (BioWare Corp.) |
| UTE |
BioWare Aurora Engine Encounter (BioWare Corp.) |
| UTE |
Rukus 110 File |
| UTF |
AOL Updating Files (America Online, Inc.) |
| UTI |
Spybot - Search & Destroy Usage Tracking (PepiMK
Software) |
| UTI |
SafeGuard PrivateCrypto Encrypted Archive (Utimaco
Safeware AG) |
| UTI |
BioWare Aurora Engine Item (BioWare Corp.) |
| UTIL |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UTIL2 |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UTILITIES |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UTILITY |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UTILS |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UTL |
Sound File |
| UTL |
QuickBooks Data (Intuit Inc.) |
| UTM |
BioWare Aurora Engine Store (BioWare Corp.) |
| UTMP |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UTP |
BioWare Aurora Engine Placeable Object (BioWare Corp.) |
| UTP |
BinPatch Patch Data File |
| UTS |
Spybot - Search & Destroy Include File (PepiMK
Software) |
| UTS |
BioWare Aurora Engine Sound (BioWare Corp.) |
| UTT |
BioWare Aurora Engine Trigger (BioWare Corp.) |
| UTW |
BioWare Aurora Engine Waypoint (BioWare Corp.) |
| UTX |
Unicode File |
| UTX |
Unreal Tournament 2003 Texture (Epic Games, Inc.) |
| UTX |
Deus Ex |
| UTX |
Harry Potter |
| UTX |
Undying |
| UTX |
Unreal / Unreal 2 |
| UTX |
Rune |
| UU |
Compressed Archive File |
| UUCP |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UUD |
Uudecoded |
| UUE |
Uuencoded |
| UUE |
Unknown Apple II File (found on Golden Orchard Apple II CD
Rom) |
| UUT |
Genesis 2000 (Genesis 2000, Inc.) |
| UV |
EA Games Video File (Electronic Arts, Inc.) |
| UV2 |
Jane's Combat Simulations F-15 |
| UVP |
ULEAD MediaStudio Video Paint Graphic (Ulead Systems,
Inc.) |
| UVR |
Ulead Cool 360 Viewer File |
| UVV |
Listlabl File |
| UVW |
geoManager/geoInterface User View |
| UVX |
Unreal Tournament 2003 Saved Game (Epic Games, Inc.) |
| UW |
Audio |
| UW |
Raw Unsigned Word (16-bit) Data |
| UW |
Unitype GlobalWriter File |
| UWF |
UltraTracker Wave File |
| UWL |
WordPerfect User Word List (Corel Corporation) |
| UWL |
GroupWise User Word List (Novell, Inc.) |
| UWS |
UniTrader 2006 Website Archive (UniTechnology Limited) |
| UWT |
UniTrader Template Archive (UniTechnology Ltd.) |
| UX |
UNIX File |
| UXD |
URLBase URL Database (Terria Development) |
| UXP |
URLBase URL Database (v. 5.1) (Terria Development) |
| UXX |
Unreal Tournament 2003 Cache (Epic Games, Inc.) |
| UXY |
Orchida Embroidery System (Orchida Soft) |
| UYVY |
Interleaved YUV Raw Image |
| UYVY |
ImageMagick Ver. 5.3.2 Perlmagick File (ImageMagick Studio
LLC) |
| UZ |
Unreal Tournament Server File |
| UZE |
Ultimate Zip Compresion Agent |
| UZR |
UZR 3D Streamable 3D File Format |
