| .jsfl |
Animate JSFL Script File |
| .jss |
JavaScript Style Sheet File |
| .jcp |
JCreator Project File |
| .j |
Java Source File |
| .jav |
Java Source File |
| .jpd |
Java Process Definition |
| .jed |
Xilinx JEDEC Programming File |
| .jsxinc |
ExtendScript Included Script File |
| .jl |
Julia Source Code File |
| .jsh |
JAWS Script Header File |
| .jnilib |
JNI Library |
| .jdp |
BlackBerry JDE Application Project |
| .jlr |
Juliar Source Code File |
| .kdevprj |
KDevelop Project File |
| .kdevelop |
KDevelop Project Data File |
| .kpl |
Kids Programming Language File |
| .kv |
Kivy Language File |
| .kt |
Kotlin Source Code File |
| .kct |
Keyman Developer Customization Source File |
| .kps |
Keyman Developer Package Source File |
| .kvk |
Keyman On-Screen Keyboard File |
| .kb |
C++ Keyboard Script |
| .kdevdlg |
KDevelop Dialog Box File |
| .kdmp |
Windows Crash Dump File |