| .HTP | Autodesk, Inc. | Ficheiros CAD | Autodesk Slope Template Definition | Autodesk AutoCAD Civil 3D | Autodesk, Inc. |
| .HUS | HUSQVARNA Viking | Ficheiros CAD | Husqvarna Embroidery File | BALARAD Embird Studio | Embird Embroidery Software Suite |
| .HYM | INUS Technology, Inc. (3D Systems) | Ficheiros CAD | Scandata 3D Scanner File | Rapidform Explorer (Geomagic Verify Viewer) | Rapidform, Inc. |
| .IAM | Autodesk, Inc. | Ficheiros CAD | Inventor Assembly File | Autodesk Fusion 360 | Autodesk, Inc. |
| .IBA | Lectra | Ficheiros CAD | Lectra Clothing Design Pieces File | PAD Pattern | PAD System International Limited |
| .ICC | Corel | Ficheiros CAD | International Color Consortium Profile File | Adobe Photoshop CC | Adobe Systems Incorporated |
| .ICD | Macrovision Corporation | Ficheiros CAD | SafeDisc Encrypted Program | SafeDisc | Macrovision Corporation |
| .ICN | Microsoft Corporation | Ficheiros CAD | Windows Icon File | Adobe Photoshop | Adobe Systems Incorporated |
| .ICS | IronCAD, LLC | Ficheiros CAD | IronCAD 3D CAD Drawing File | IronCAD | IronCAD, LLC |
| .ICW | Microsoft Corporation | Ficheiros CAD | Microsoft Internet Explorer Internet Connection Wizard Data | Internet Explorer | Microsoft Corporation |
| .IDE | Rockstar Games | Ficheiros CAD | GTA Item Definition File | Grand Theft Auto IV | Rockstar Games |
| .IDV | Autodesk, Inc. | Ficheiros CAD | Inventor Design View File | Autodesk Inventor | Autodesk, Inc. |
| .IDW | Autodesk, Inc. | Ficheiros CAD | Inventor Drawing | Autodesk Inventor | Autodesk, Inc. |
| .IGS | United States Air Force | Ficheiros CAD | Initial Graphics Exchange Specification Drawing File | SOLIDWORKS | Dassault Systèmes |
| .IMW | Unknown Developer | Ficheiros CAD | Imageware Surfacer 3D CAD Surface Geometry File | Unknown Software | Unknown Developer |
| .INFINI-D | Unknown Developer | Ficheiros CAD | Infini-D 3.0 Format | Unknown Software | Unknown Developer |
| .IPJ | Autodesk, Inc. | Ficheiros CAD | Inventor Project File | Autodesk Inventor | Autodesk, Inc. |
| .IPT | Autodesk, Inc. | Ficheiros CAD | Inventor Part File | Autodesk Fusion 360 | Autodesk, Inc. |
| .ISO | Igor Pavlov | Ficheiros CAD | Disc Image File | 7-Zip | Igor Pavlov |
| .JAM | Sierra Entertainment | Ficheiros CAD | Leisure Suit Larry Magna Cum Laude Archive File | Leisure Suit Larry: Magna Cum Laude | Sierra Entertainment |
| .JBC | Altera | Ficheiros CAD | Jam STAPL Byte-Code File | Jam STAPL Byte-Code Player | Altera |
| .JOB | Metamation | Ficheiros CAD | MetaCAM Nest Job File | MetaCAM Nesting | Metamation |
| .JT | Siemens PLM Software | Ficheiros CAD | JT Open CAD File | Siemens PLM NX | Siemens PLM Software |
| .JVSG | JVSG | Ficheiros CAD | Video Surveillance Project | JVSG IP Video System Design Tool | JVSG |
| .JWW | Open Source | Ficheiros CAD | Java Web-Workflows Data | Java Web-Workflows | Open Source |
| .KIT | Bryan | Ficheiros CAD | CodeKit File | CodeKit | Bryan |
| .KRP | ISD Group | Ficheiros CAD | HiCad 3D Part File | HiCAD neXt | ISD Group |
| .L2D | Cadwork SA | Ficheiros CAD | Cadwork File | Cadwork | Cadwork SA |
| .LAY6 | ABACOM | Ficheiros CAD | Sprint-Layout Document | Sprint-Layout | ABACOM |
| .LCF | Graphisoft | Ficheiros CAD | ArchiCAD Library Container File | ARCHICAD | Graphisoft |
| .LDT | DIAL | Ficheiros CAD | Eulumdat Formatted Luminaire Data File | DIAL DIALux | DIAL |
| .LEG | Interscape | Ficheiros CAD | LEGOCAD File | LEGOCAD | Interscape |
| .LIN | Autodesk, Inc. | Ficheiros CAD | AutoCAD Linetype File | Autodesk AutoCAD | Autodesk, Inc. |
| .LK# | Autodesk, Inc. | Ficheiros CAD | Autodesk Multi-User Coordination Lock Data | Autodesk AutoCAD Civil 3D | Autodesk, Inc. |
| .LY+ | DataCAD LLC | Ficheiros CAD | DataCAD Plus Layer File | DataCAD | DataCAD LLC |
| .LYC | SPGPrints Group | Ficheiros CAD | BestIMAGE Compressed Design File | spgprints bestIMAGE | SPGPrints Group |
| .LYR | ESRI | Ficheiros CAD | ArcView Layer File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .MAGICS | Materialise | Ficheiros CAD | Magics Project File | Magics e-RP Suite | Materialise |
| .MC3 | Interactive Design Systems (IDS) | Ficheiros CAD | Bridge Design Modeler 3D Match-casting Geometry Control | BD3 | Interactive Design Systems (IDS) |
| .MC8 | CNC Software | Ficheiros CAD | Mastercam V8 File | Mastercam | CNC Software |
| .MC9 | CNC Software | Ficheiros CAD | Mastercam 9 Geometry File | Mastercam | CNC Software |
| .MCD | Nemetschek Group | Ficheiros CAD | MiniCAD Design File | Vectorworks Viewer | Vectorworks |
| .MCX-6 | CNC Software | Ficheiros CAD | Mastercam X6 3D Model | Mastercam | CNC Software |
| .MDL | MathWorks | Ficheiros CAD | MathWorks Simulink Model | Simulink | MathWorks |
| .MF2 | Adobe Systems Incorporated | Ficheiros CAD | Authorware Mediator5 Multimedia File | Adobe Authorware | Adobe Systems Incorporated |
| .MHE | Procedimientos-Uno, S.L. | Ficheiros CAD | MHwinEHE Project | MHwinEHE | Procedimientos-Uno, S.L. |
| .MHS | Xilinx, Inc. | Ficheiros CAD | Xilinx XPS Hardware Specification File | Xilinx Platform Studio (XPS) | Xilinx, Inc. |
| .MIN | Okuma | Ficheiros CAD | Okuma CNC Program File | Microsoft Notepad | Microsoft Corporation |
| .MKD | Malz++Kassner | Ficheiros CAD | CAD 6 Drawing File | CAD6 Studio | Malz++Kassner |
| .MKH | SYNRAD | Ficheiros CAD | WinMark Pro Mark Data | WinMark Pro | SYNRAD |
| .MKL | Malz++Kassner | Ficheiros CAD | Malz++Kassner CAD Library File | CAD6 Studio | Malz++Kassner |
| .MLI | Unknown Developer | Ficheiros CAD | Encyclopedia Media List | Unknown Software | Unknown Developer |
| .MOD | Open Source | Ficheiros CAD | Amiga Music Module File | ModPlug Player | Open Source |
| .MODEL | Dassault Systèmes | Ficheiros CAD | MODEL | Dassault Systemes CATIA | Dassault Systèmes |
| .MS9 | National Instruments | Ficheiros CAD | Multisim 9 Circuit Design File | NI Multisim | National Instruments |
| .MSD | ESRI | Ficheiros CAD | Map Service Definition File | ESRI ArcGIS for Desktop | ESRI (Environmental Systems Research Institute) |
| .MSH | Martin Schweiger | Ficheiros CAD | Orbiter 3D Mesh File | Orbiter | Martin Schweiger |
| .MVS | Xilinx, Inc. | Ficheiros CAD | Microchip Verification Specification File | Xilinx Platform Studio (XPS) | Xilinx, Inc. |
| .NC | CNC Software | Ficheiros CAD | Mastercam Numerical Control File | Mastercam | CNC Software |
| .NC1 | CNC Software | Ficheiros CAD | Mastercam Numerical Control File | Mastercam | CNC Software |
| .NCZ | Netcad | Ficheiros CAD | Netcad Drawing | Netcad | Netcad |
| .NEU | Parametric Technology Corporation | Ficheiros CAD | Pro/ENGINEER Neutral File | Creo Parametric 3D Modeling Software | PTC |
| .NGD | Xilinx, Inc. | Ficheiros CAD | Xilinx Netlist File | ISE Design Suite | Xilinx, Inc. |
| .NPL | Nokia | Ficheiros CAD | Nokia Playlist File | Nokia Multimedia Player | Nokia |
| .NWC | NoteWorthy Software | Ficheiros CAD | NoteWorthy Composer File | NoteWorthy Composer | NoteWorthy Software |
| .NWD | Autodesk, Inc. | Ficheiros CAD | Navisworks Document | Navisworks | Autodesk, Inc. |
| .NWF | Autodesk, Inc. | Ficheiros CAD | Navisworks File Set | Navisworks | Autodesk, Inc. |
| .OCD | Ocad Inc. | Ficheiros CAD | OCAD Map File | OCAD | Ocad Inc. |
| .OFE | Unknown Developer | Ficheiros CAD | 3D Boat Design File | Model Converter | Creative Systems |
| .OL | Valve | Ficheiros CAD | Valve Hammer Object Layout File | Valve Hammer Editor | Valve |
| .OLB | Microsoft Corporation | Ficheiros CAD | OLE Object Library | Microsoft Excel | Microsoft Corporation |
| .OPJ | Cadence Design Systems | Ficheiros CAD | OrCAD Project File | OrCAD PCB Designer | Cadence Design Systems |
| .OPT | LexisNexis | Ficheiros CAD | Concordance Database File | LexisNexis Concordance | LexisNexis |
| .P2D | WDV-INFORMATIK AG | Ficheiros CAD | PointLineCAD 2D Drawing | PointLine2D | WDV-INFORMATIK AG |
| .P3L | Adobe Systems Incorporated | Ficheiros CAD | Adobe Photoshop Light Preset File | Adobe Photoshop | Adobe Systems Incorporated |
| .PAR | Siemens PLM Software | Ficheiros CAD | Solid Edge Part File | Adobe Acrobat DC | Adobe Systems Incorporated |
| .PAT | Autodesk, Inc. | Ficheiros CAD | AutoCAD Hatch Pattern File | Autodesk AutoCAD | Autodesk, Inc. |
| .PCS | Pfaff | Ficheiros CAD | Pfaff Embroidery File | PesView | Open Source |
| .PHO | Ucamco | Ficheiros CAD | Gerber Photoplot File | Altium Designer | Altium |
| .PHV | HUSQVARNA Viking | Ficheiros CAD | Husqvarna Viking 3D Embroidery Design | 3D Embroidery | VSM Group |
| .PIPE | Engineered Software Inc. | Ficheiros CAD | PIPE-FLO Project File | Engineered Software PIPE-FLO | Engineered Software Inc. |
| .PLAN | KDE | Ficheiros CAD | Calligra Plan Document | Calligra Suite | KDE |
| .PLJ | Nirvana Technologies | Ficheiros CAD | PLUS 2D Job File | Plus 2D | Nirvana Technologies |
| .PLN | Microsoft Corporation | Ficheiros CAD | Flight Simulator Flight Plan | Microsoft Flight Simulator | Microsoft Corporation |
| .PM3 | Crouzet | Ficheiros CAD | Crouzet Logic Software M3 File | Crouzet M3 Soft | Crouzet |
| .POB | Encore Software Inc. | Ficheiros CAD | Punch CAD Object | Punch! Home Design | Encore Software Inc. |
| .PPV | Microsoft Corporation | Ficheiros CAD | Pocket PowerPoint Presentation | Microsoft PowerPoint | Microsoft Corporation |
| .PRA | SofTech, Inc. | Ficheiros CAD | CADRA Design Drafting Software Data | CADRA | SofTech, Inc. |
| .PRG | Open Source | Ficheiros CAD | Program File | Notepad++ | Don Ho |
| .PRO | Adobe Systems Incorporated | Ficheiros CAD | Adobe Proto Design File | Adobe Dreamweaver | Adobe Systems Incorporated |
| .PRT | PTC | Ficheiros CAD | Pro/ENGINEER Part File | Autodesk Fusion 360 | Autodesk, Inc. |
| .PRTDOT | Dassault Systèmes | Ficheiros CAD | SolidWorks Part Template | Dassault Systemes SolidWorks | Dassault Systèmes |
| .PS5 | Greentram Software | Ficheiros CAD | ProSteel 5 Data File | ProSteel | Greentram Software |
| .PSF | Adobe Systems Incorporated | Ficheiros CAD | Photoshop Proof Settings File | Adobe Photoshop Elements | Adobe Systems Incorporated |
| .PSL | Ericom Software | Ficheiros CAD | PowerTerm Script Language File | PowerTerm InterConnect | Ericom Software |
| .PSM | Embarcadero Technologies | Ficheiros CAD | Turbo Pascal Symbol Table Of IDE | Turbo Pascal | Embarcadero Technologies |
| .PSMODEL | Autodesk, Inc. | Ficheiros CAD | PowerSHAPE 3D Model File | PowerSHAPE | Autodesk, Inc. |
| .PSS | Autodesk, Inc. | Ficheiros CAD | AutoCAD Plot Stamp Settings File | Autodesk AutoCAD | Autodesk, Inc. |
| .PSV | Sony | Ficheiros CAD | PlayStation 2 Save File | PSV Exporter | Open Source |
| .PWD | Microsoft Corporation | Ficheiros CAD | Microsoft Pocket Word Document | Softmaker Office | SoftMaker Software |
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