.U | Epic Games | Ficheiros de Jogo | Unreal Tournament Class Package | Dragon UnPACKer | Open Source |
.U8 | Nintendo | Ficheiros de Jogo | Mario Kart Wii Archive File | Wiimms SZS Toolset | Nintendo |
.UBI | Ubisoft | Ficheiros de Jogo | Ubisoft Logo Animation | Unknown Software | Unknown Developer |
.UC | Epic Games | Ficheiros de Jogo | UnrealScript Class | UnrealEd | Epic Games |
.UCL | Tripwire, Inc. | Ficheiros de Jogo | Killing Floor System File | Killing Floor | Tripwire Interactive |
.UCM | FAKT Software | Ficheiros de Jogo | Crazy Machines Model File | Crazy Machines | FAKT Software |
.UCS | Relic Entertainment | Ficheiros de Jogo | Relic Localized Unicode Strings | Homeworld 2 | Sierra Entertainment |
.UDM | Motcreations Software Inc. | Ficheiros de Jogo | MapView User-Defined Module File | MapView Virtual Gaming System | Motcreations Software Inc. |
.UFO | Ulead Systems | Ficheiros de Jogo | Ulead File Object | Ulead Photo Express | Ulead Systems |
.UGI | Paterva | Ficheiros de Jogo | MultiGo Game Data | MultiGo | Paterva |
.UH | Ensemble Studios | Ficheiros de Jogo | Age Of Empires II (The Age Of Kings) File | Age of Empires II | Microsoft Corporation |
.UHTM | Epic Games | Ficheiros de Jogo | Unreal Tournament Data File | Unreal Tournament | Epic Games |
.UKX | Epic Games | Ficheiros de Jogo | Unreal Animation Package | Dragon UnPACKer | Open Source |
.UMAP | Epic Games | Ficheiros de Jogo | Unreal Engine Map File | Unreal Tournament | Epic Games |
.UMD | Ubisoft | Ficheiros de Jogo | Splinter Cell Blacklist Game Data File | Splinter Cell Blacklist | Ubisoft |
.UMOD | Epic Games | Ficheiros de Jogo | Unreal Tournament Module File | Unreal Tournament | Epic Games |
.UMV | Viacom New Media | Ficheiros de Jogo | Are You Afraid Of The Dark? Video Data | Are You Afraid of the Dark? The Tale of Orpheo's Curse | Viacom New Media |
.UMX | Epic Games | Ficheiros de Jogo | Unreal Music Package | VLC Media Player | VideoLAN |
.UNF | Open Source | Ficheiros de Jogo | UNIF ROM File | Nestopia | Open Source |
.UNR | Unreal Software | Ficheiros de Jogo | Unreal Level Map | UnrealEd | Epic Games |
.UPK | Epic Games | Ficheiros de Jogo | Unreal Engine 3 Package | Unreal Tournament | Epic Games |
.UPS | Open Source | Ficheiros de Jogo | UPS Patch File | MultiPatch patching tool | Open Source |
.UQM | Toys for Bob | Ficheiros de Jogo | The Ur-Quan Masters Archive File | The Ur-Quan Masters | Toys for Bob |
.USA | Microsoft Corporation | Ficheiros de Jogo | American English Localization Language File | Microsoft Notepad | Microsoft Corporation |
.USX | Epic Games | Ficheiros de Jogo | Unreal Static Meshes | Dragon UnPACKer | Open Source |
.UT2 | Epic Games | Ficheiros de Jogo | Unreal Tournament 2003/2004 Map | Unreal Tournament | Epic Games |
.UT2MOD | Epic Games | Ficheiros de Jogo | Unreal Tournament 2003/2004 Module File | Unreal Tournament 2003 | Epic Games |
.UT3 | Epic Games | Ficheiros de Jogo | Unreal Tournament 3 Map File | Unreal Tournament | Epic Games |
.UT4MOD | Epic Games | Ficheiros de Jogo | Unreal Tournament 2004 MOD Installation Package File | Unreal Tournament 2004 | Epic Games |
.UTB | Unknown Developer | Ficheiros de Jogo | µTBackup Backup | µTBackup | Unknown Developer |
.UTC | BioWare | Ficheiros de Jogo | BioWare Aurora Game Engine Creature Data File | Various video games | Various Developers |
.UTD | BioWare | Ficheiros de Jogo | BioWare Aurora Game Engine Door File | BioWare Neverwinter Nights | BioWare |
.UTI | BioWare | Ficheiros de Jogo | Bioware Aurora Item Data | BioWare Neverwinter Nights | BioWare |
.UTP | BioWare | Ficheiros de Jogo | BioWare Aurora Game Engine Placeable Object File | BioWare Neverwinter Nights | BioWare |
.UTS | BioWare | Ficheiros de Jogo | BioWare Aurora Game Engine Sound File | BioWare Neverwinter Nights | BioWare |
.UTT | BioWare | Ficheiros de Jogo | Bioware Trigger File | BioWare Neverwinter Nights | BioWare |
.UTW | BioWare | Ficheiros de Jogo | BioWare Aurora Engine Waypoint File | BioWare Neverwinter Nights | BioWare |
.UTX | Epic Games | Ficheiros de Jogo | Unreal Texture Package | Dragon UnPACKer | Open Source |
.UV2 | Electronic Arts | Ficheiros de Jogo | Jane's Combat Simulations: F-15 Game Data File | Jane's Combat Simulations: F-15 Game | Electronic Arts |
.UVX | Epic Games | Ficheiros de Jogo | Unreal Tournament 2003 Saved Game File | Unreal Tournament 2003 | Epic Games |
.UXX | Epic Games | Ficheiros de Jogo | Unreal Tournament 2003 Cache File | Unreal Tournament 2003 | Epic Games |