| .ias |
Intermodulation Analysis System File |
| .icmod |
Inner Core Minecraft PE Mod File |
| .jar |
Java Archive File |
| .jic |
JTAG Indirect Configuration File |
| .jvsgz |
Compressed Video Surveillance Project |
| .key |
Software License Key File, Apple's Keynote software file, keyboard definition file |
| .kmz |
Google Earth Placemark File |
| .ksf |
KMPlayer Skin File |
| .kds |
KD Player Skin File |
| .kdi |
KD Player Skin Image File |
| .moho |
Moho Animation Project |
| .masseffectsave |
Mass Effect Saved Game |
| .m2p |
MPEG-2 Program Stream File |
| .mshc |
Microsoft Help Container File |
| .mpz |
Miradi Project File |
| .maff |
Mozilla Archive Format File |
| .mga |
Manga Document |
| .mcworld |
Minecraft World Backup File |
| .mmip |
MediaMonkey Installation Package |
| .mdzip |
MagicDraw Project Archive |
| .mcpack |
Minecraft Resource Pack File |
| .mpzip |
Multisim Pack File |
| .mcgame |
Minecraft Game Backup File |
| .mmz |
MiraMon Compressed Map File |