| joy | CryENGINE Facial Editor Joystick Settings |
| jpb | J Publish Manager Data |
| jpd | Java Process Definition |
| jpf | Java PathFinder Application Property Data |
| jph | JProbe Memory Snapshot |
| jpl | JProbe Settings |
| jpq | JPQ Library |
| jpt | JProbe Threadalyzer Memory Snapshot |
| jpy | JPY Data |
| jr | JR Source Code |
| jrag | JastAdd Declarative Aspect |
| jrprint | JasperReports Print Document |
| jrxml | JasperReports Document |
| js | JavaScript |
| js | JavaScript Style Sheet |
| jsa | JRun Server Application |
| jsb | JAWS Script Binary File |
| jsb | JavaScript Bean |
| jsc | Jeroo Source Code |
| jsc | Rhino Compiled Javascript |
| jscript | Windows Media Player JScript |
| jsd | JAWS Script Documentation File |
| jsdtscope | Eclipse IDE JavaScript Development Tool Scope Data |
| jsfl | Flash JavaScript |
| jsh | Jsh Script |
| jsh | JAWS Script Header |
| jsl | JMP Scripting Language File |
| jsm | JavaScript Module |
| jsm | JAWS Script Message File |
| jsp | Java Servlet |
| jspa | Java Servlet Alias |
| jspf | Java Server Page Fragment |
| jspx | Java Servlet XML |
| jss | JavaScript Style Sheet |
| jss | JAWS Script Source |