| androidproj | Microsoft Visual Studio Android Project |
| animeproj | Anime Studio Project |
| anjuta | Anjuta DevStudio Project |
| ap12 | Siemens TIA v12 Project |
| ap13 | TIA Portal v13 Project |
| ap14 | TIA Portal v14 Project |
| ap15 | SIMATIC WinCC v15 Project |
| ap16 | TIA Portal v16 Project |
| ap17 | TIA Portal v17 Project |
| ap3 | Asprova Project |
| apj | Angel Debug Monitor Project |
| Archibus Project Preferences Data |
| ARM Project Manager Project |
| Autodesk AutoCAD Architecture Project |
| apk | Active Tutor Project |
| app | CA Visual Objects Project |
| approj | ActivePresenter Project |
| apr | Apadana Project |
| Vector NTI Alignment Project |
| aprj | ApacheConf Project |
| aproj | Leapfrog Geo Project |
| aprx | Vector NTI Alignment Project |
| apt | appTranslator Project |
| AutoPlay Media Studio Template |
| apz | Autoplay Media Studio Exported Project |
| architect | SQL Power Architect Project |
| arcproj | ARRIRAW Converter Project |
| argo | ArgoUML Project |
| arh | ArheoStratigraf Project |
| Siemens ProTool Compressed Project |
| arp | Arlequin Project |
| arproj | Spark AR Studio Project |
| art42 | Bernina Explorations v1.x Project |
| art50 | Bernina Embroidery Software v5.0 Design |
| art60 | Bernina Embroidery Software v6.0 Design |
| artproj | Artifacts for Visual Studio Project |
| artx | Artisteer Project |
| as2proj | FlashDevelop Project |
| as3proj | FlashDevelop Project |
| asdvdcrtproj | Aimersoft DVD Creator Project |
| ashprj | Ashampoo Burning Studio Project |
| asmproj | Atmel Studio Assembler Project |
| asprj | Altova XMLSpy Scripting Project |
| asproj | Visual Studio Analysis Services Project |
| assembly | DNASTAR SeqMan NGen Assembly Project |
| asta | Astah Project |
| astah | Astah Project |
| asw | ACDSee Slideshow Wizard Project |
| ata | Antenna Web Design Studio Project |
| atgcproj | Genetyx ATGC Project |
| atlcb | ATLAS.ti 7 Copy Bundle |
| atlpac | ATLAS.ti 1 Transfer Bundle |
| atlproj | ATLAS.ti 8 Project Bundle |
| ato | ATO Modeler Project |
| atp | Automise Project |
| Visual Studio ACT Project |
| atpz | Automise Compressed Project |
| atsuo | Atmel Studio Project |
| atx5 | Automise 5 XML Project |
| atz3 | Automise 3 Project |
| atz4 | Automise 4 Project |
| aud | Audacity Project |
| Audacity v3 Project |
| aup | Audacity Project |
| aup3 | Audacity v3 Project |
| aurx | AutoREALM Project |
| autoplay | AutoPlay Media Studio Project |
| avenirproj | StoryMill Project |
| avp | Avid Media Composer Project |
| avrasmproj | Atmel Studio Legacy Assembler Project |
| awx | ArcIMS XML Project |
| axp | AppGini v3 Project |
| b4f | Burn4Free Project |
| bamp | Easy Button and Menu Maker Project |
| band | GarageBand Project |
| baseproj | DNA Baser Sequence Alignment Project |
| baserproj | DNA Baser Sequence Alignment Project |
| bbmodel | Blockbench Project |
| bbproject | BBEdit Project |
| bbprojectd | BBEdit Project Package |
