IDL
- ICAD (software)
- IDL specification language
- Indianola Municipal Airport
- Interactive Data Language
- Interface description language
- Intermediate-density lipoprotein
- International Darts League
- International Date Line
- International Drivers License
- Internet Defense League
- Interstate 444
- Islamic Democratic League
- John F. Kennedy International Airport
- Microsoft Interface Definition Language
- OMG IDL
- Web IDL