| .GTM | Open Source | GIS Files | GreekToMe Translation File | GreekToMe | Open Source |
| .GTZ | TrackMaker | GIS Files | GPS TrackMaker Data File | GPS TrackMaker | TrackMaker |
| .GVR | GeoVisu Development Team | GIS Files | GeoVisu Routes File | GeoVisu | GeoVisu Development Team |
| .GWC | SISCOSOFT | GIS Files | Golfwits Course Map File | Golfwits | SISCOSOFT |
| .GWS | Intergraph Corporation | GIS Files | GeoMedia GeoWorkspace File | Intergraph GeoMedia | Hexagon Geospatial |
| .GXW | Open Source | GIS Files | GRASS GIS Workspace File | GRASS | Open Source |
| .HDR | HDRsoft | GIS Files | High Dynamic Range Image File | HDRSoft Photomatix | HDRsoft |
| .HDS | Parallels | GIS Files | Parallels Desktop Hard Disk File | Parallels Desktop for Mac | Parallels |
| .HGT | Safe Software | GIS Files | SRTM Elevation Data File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .HNR | Unknown Developer | GIS Files | Teleatlas Data | iGO Navigation | NNG |
| .HR4 | PCI Geomatics | GIS Files | Geomatica High Resolution Elevation | PCI Geomatica | PCI Geomatics |
| .HTF | Australian Government | GIS Files | Hydrographic Transfer Format | GDAL | Open Source |
| .HWM | ISYS | GIS Files | Own Raster Map Parameters | MapWise | ISYS |
| .IKT | MagicMaps | GIS Files | MagicMaps IK3D Project | IK3D | MagicMaps |
| .ILF | Open Source | GIS Files | Alim File | Alim | Open Source |
| .IMD | Various Developers | GIS Files | GIS Image Metadata File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .IMG | Unknown Developer | GIS Files | Disk Image Data File | IsoBuster | Smart Projects |
| .IMI | Embarcadero Technologies | GIS Files | Turbo Pascal DOS File | Turbo Pascal | Embarcadero Technologies |
| .IRV | DeLorme | GIS Files | XMap Workfile File | XMap | Garmin |
| .IXC | ESRI (Environmental Systems Research Institute) | GIS Files | ArcView Geocoding Index For Read-Write Coverages File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .J2W | ESRI | GIS Files | ArcExplorer World | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .JCT | SourceForge | GIS Files | JCT File | JCT | SourceForge |
| .JFW | ESRI | GIS Files | JPEG World File | Microsoft Notepad | Microsoft Corporation |
| .JGW | ESRI | GIS Files | JPEG World File | Microsoft Notepad | Microsoft Corporation |
| .JNX | Oliver Eichler | GIS Files | BirdsEye JNX Raster Map | Garmin BaseCamp | Garmin |
| .JPR | Microsoft Corporation | GIS Files | WordPad Document | Microsoft WordPad | Microsoft Corporation |
| .KEY | Unknown Developer | GIS Files | License/ Encrypted Security Key File | Avira Antivirus Pro 2016 | Avira Operations GmbH & Co. KG. |
| .KLM | Google | GIS Files | Google Earth Path File | Google Earth | Google |
| .KML | Keyhole Corporation | GIS Files | Keyhole Markup Language File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .KMZ | Google | GIS Files | Google Earth Placemark File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .KWI | Unknown Developer | GIS Files | KIWI Navigation System Database | KIWI GPS navigation systems | Unknown Developer |
| .LAN | ESRI (Environmental Systems Research Institute) | GIS Files | ERDAS LAN File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .LAZ | Global Heavy Industries | GIS Files | LiquidApps Project File | Liquid Studio | Global Heavy Industries |
| .LEN | Hexagon Geospatial | GIS Files | IMAGINE Lens Flare File | ERDAS Imagine | Hexagon Geospatial |
| .LGS | Microsoft Corporation | GIS Files | Microsoft Windows Application Log File | Microsoft Windows | Microsoft Corporation |
| .LPK | ESRI | GIS Files | ArcGIS Layer Package | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .LXN | Naviter | GIS Files | SeeYou Flight Data File | SeeYou | Naviter |
| .MAP | id Software | GIS Files | Quake Engine Map File | Valve Hammer Editor | Valve |
| .MDC | IBM | GIS Files | Multi Dimension Cube File | Cognos software | IBM |
| .MID | Open Source | GIS Files | MIDI Audio File | Microsoft Windows Media Player | Microsoft Corporation |
| .MIF | Adobe Systems Incorporated | GIS Files | FrameMaker Interchange Format File | Adobe FrameMaker | Adobe Systems Incorporated |
| .MMM | Magix Software GmbH | GIS Files | Music Maker Arrangement File | MAGIX Music Maker | Magix Software GmbH |
| .MMZ | CREAF and UAB | GIS Files | MiraMon Compressed Map File | MiraMon | CREAF and UAB |
| .MPK | ESRI | GIS Files | ArcGIS Map Package | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .MPS | IBM | GIS Files | Mathematical Programming System File | Vim | Bram Moolenaar |
| .MRR | Pitney Bowes | GIS Files | MapInfo Map Data | MapInfo Professional | Pitney Bowes |
| .MSD | ESRI | GIS Files | Map Service Definition File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .MTC | Make The Cut, LLC | GIS Files | Make The Cut! Project | Make the Cut! | Make The Cut, LLC |
| .MWM | Keen Software House | GIS Files | Space Engineers Model | Space Engineers | Keen Software House |
| .MXD | ESRI | GIS Files | ArcGIS Map Document | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .MXS | Next Limit Technologies | GIS Files | Maxwell Studio Scene File | Maxwell Render | Next Limit Technologies |
| .MXT | ESRI | GIS Files | ArcGIS Map Template | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .NFS | Codemasters | GIS Files | F1 2015 Speech Data | F1 2015 | Codemasters |
| .NIT | ESRI | GIS Files | ArcView INFO Table Definitions File | ArcView | ESRI |
| .NM2 | Navitel S.R.O. | GIS Files | Navitel Map | Navitel Navigator | Navitel S.R.O. |
| .NMF | ESRI | GIS Files | ArcGIS Explorer Map File | Internet Explorer | Microsoft Corporation |
| .NTM | Navitel S.R.O. | GIS Files | Navitel Map | Navitel Navigator | Navitel S.R.O. |
| .NV2 | Q.W.Page Associates Inc | GIS Files | NewViews 2 Database File | Q.W. Page NewViews 2 | Q.W.Page Associates Inc |
| .NVI | NVIDIA | GIS Files | NVIDIA Driver File | NVIDIA Graphics Driver | NVIDIA |
| .OCD | Ocad Inc. | GIS Files | OCAD Map File | OCAD | Ocad Inc. |
| .OCP | Zylox Software, Inc. | GIS Files | Offline Commander Project File | Offline Commander | Zylox Software, Inc. |
| .OKM | Gian Paolo Saliola | GIS Files | OkMap Map Defining File | OkMap | Gian Paolo Saliola |
| .OMD | Pitney Bowes | GIS Files | MapInfo Routing J Server Data | MapInfo Professional | Pitney Bowes |
| .OSB | Bart Vanhauwaert, Chris Browet, Ladislav Láska, and others | GIS Files | OpenStreetMap Binary Map File | Merkaartor | Bart Vanhauwaert, Chris Browet, Ladislav Láska, and others |
| .OSC | OpenStreetMap | GIS Files | OpenStreetMap Change File | Merkaartor | Bart Vanhauwaert, Chris Browet, Ladislav Láska, and others |
| .OSL | Ockam Instruments | GIS Files | OckamSoft Log File | OckamSoft | Ockam Instruments |
| .OSM | OpenStreetMap | GIS Files | OpenStreetMap Map File | Merkaartor | Bart Vanhauwaert, Chris Browet, Ladislav Láska, and others |
| .OV2 | TomTom International BV | GIS Files | TomTom POI (Points Of Interest) Database | TomTom HOME | TomTom NV |
| .OZF2 | D & L Software Pty Ltd | GIS Files | OziExplorer Map File | OziExplorer | D & L Software Pty Ltd |
| .OZFX3 | D & L Software Pty Ltd | GIS Files | OziExplorer Image | OziExplorer | D & L Software Pty Ltd |
| .PIN | Sapper Oy | GIS Files | MNS Projection Information File | Master Navigation Software | Sapper Oy |
| .PIX | PCI Geomatics | GIS Files | PCI Geomatics Database File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .PMF | ESRI | GIS Files | ESRI Published Map File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .PNA | PhatNoise (Harman International) | GIS Files | PhatNoise Audio File | PhatNoise Music Manager | PhatNoise (Harman International) |
| .PP2 | Pingman Tools | GIS Files | PingPlotter Data File | PingPlotter | Pingman Tools |
| .PPC | Garmin | GIS Files | XMap Flight Plan Statistic File | XMap | Garmin |
| .PPS | Microsoft Corporation | GIS Files | PowerPoint Slide Show | Apache OpenOffice | Apache Software Foundation |
| .PR5 | GEOTOP | GIS Files | MapSys Map File | MapSys | GEOTOP |
| .PRC | Adobe Systems Incorporated | GIS Files | Product Representation Compact File | Adobe Acrobat DC | Adobe Systems Incorporated |
| .PRM | Unknown Developer | GIS Files | Parameter File | GSAS | National Institute of Standards and Technology (NIST) |
| .PTM | Microsoft Corporation | GIS Files | MapPoint Map File | Microsoft MapPoint | Microsoft Corporation |
| .PTT | Avid Technology | GIS Files | Pro Tools Session Template | Avid Pro Tools | Avid Technology |
| .QAL | Sawpit Software | GIS Files | OpenMap Quality Data | OpenMap | Sawpit Software |
| .QCT | Memory-Map | GIS Files | Memory-Map Imported Map File | Memory-Map Navigator | Memory-Map |
| .QED | Memory-Map | GIS Files | Memory-Map Navigator Map File | Memory-Map Navigator | Memory-Map |
| .QRT | Mats Troeng and Jörgen Ohlin | GIS Files | QuickRoute Map | QuickRoute | Mats Troeng and Jörgen Ohlin |
| .RDC | IBM | GIS Files | IBM Voice Type Languages Scripts Data File | Mozilla Firefox | Mozilla |
| .RDF | Unknown Developer | GIS Files | Resource Description Framework File | Mozilla Firefox | Mozilla |
| .REF | Clark Labs | GIS Files | IDRISI Raster Image Reference File | GDAL | Open Source |
| .RESP | IRIS | GIS Files | IRIS RESP File | rdseed | IRIS |
| .RGN | Garmin | GIS Files | Garmin Regional Data File | MapInstall | Garmin |
| .RIK | Open Source | GIS Files | SharpMap File | SharpMap | Open Source |
| .RMP | RealNetworks | GIS Files | RealPlayer Metadata Package File | Apple iTunes | Apple |
| .RRD | Unknown Developer | GIS Files | Reduced Resolution Dataset File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .RST | David Goodger | GIS Files | ReStructuredText File | Microsoft Notepad | Microsoft Corporation |
| .RTE | Autodesk, Inc. | GIS Files | Revit Project Template | AutoCAD Architecture | Autodesk, Inc. |
| .RTX | The Document Foundation | GIS Files | Rich Text Document | LibreOffice | The Document Foundation |
| .SA4 | DeLorme | GIS Files | Delorme Street Atlas USA File | DeLorme Street Atlas USA | DeLorme |
| .SA7 | DeLorme | GIS Files | Street Atlas 7 Map Document | DeLorme Street Atlas USA | DeLorme |
| .SA8 | DeLorme | GIS Files | Street Atlas 8 Map Document | DeLorme Street Atlas USA | DeLorme |
of 3 
