| lgv | Windows Logger Log |
| lgw | ANSYS Saved Log |
| lh | LayaAir Sprite3D Data |
| lhd | ERL Server Database |
| lhi | ERL Server Index Data |
| lhi | TOPOG Landslide Hazard Index Data |
| lhm | ERL Server Metadata |
| lhp | Lighthouse Organizer Data |
| lhr | Intuit Quicken Financial Life for Mac File |
| li | Moku:Lab Data |
| li5 | LOGINventory 5 Data |
| lia | P-CAD Schematics Library |
| lib | FluidDraw Library |
| lib | Maple Repository Data File |
| lib | TINA Library |
| lib4d | Maxon Cinema 4D Preset Library |
| libpkg | Altium Designer Integrated Library Package |
| library | Catia Library |
| library-ms | Windows Library Description |
| lic | General License File |
| lickey | AVS4YOU License Key Data |
| lidata | LiDAR360 Data |
| lif | Intuit TurboTax Information Archive |
| lig | Afm2pl Ligkern Specifications |
| lij | Apple Photos Data |
| lijs | Apple Photos Data |
| lim | LIMP Impedance Data |
| lims | Liquid Injection Molding Simulation Data |
| lin | Autodesk AutoCAD Linetypes |
| lin | LISCAD Line Styles Data |
| linf | LinF Source Code |
| link | iPod Link Data |
| linx | iPod Links Folder Data |
| lir | CAP42 License Request File |
| lis | SQR Printer Output |