| Abbreviation | Definition |
|---|---|
| IV-VRML | Inventor VRML Format document |
| IW | IconAuthor Presentation flowchart |
| IW | Idlewild Screensaver file |
| IWA | Text document (IBM Writing Assistant) |
| IWP | Text document (Wang) |
| IX | Linker information (Modula-3) |
| IZT | Binary token file (IZL) |
| JA | Japan Agricultural |
| JAM | Jam messagebase (FTN software) |
| JAM | JamTracker Music module |
| JAR | Java ARchive |
| JAS | JAS Compressed Bitmap graphics |
| JASC | JAS Compressed Graphics file |
| JAV | Java language source code file |
| JAVA | Java language source code file |
| JBD | Datafile (SigmaScan) |
| JBF | Jasc Browser File |
| JBIG | Joint Bilevel Image Group Bitmap graphics (1-bit raster image) |
| JBX | Project Scheduler 4 Project file |
| JCM | Java commerce message |