| lrdb | Adobe Photoshop Lightroom 1.0 Database |
| lrl | SmartWare Local Resource Library |
| lrm | Microsoft Encarta Class Server Learning Resource Module |
| lrpreview | Adobe Photoshop Lightroom Preview |
| lrq | GEAR License Request File |
| lrr | HPE LoadRunner Raw Results |
| lrreg | Adobe Photoshop Lightroom License Data |
| lrtemplate | Adobe Photoshop Lightroom Template |
| lrtoolkit | Adobe Photoshop Lightroom Toolkit Data |
| ls | Lightscape Solution File |
| ls | LayaAir Scene Data |
| ls | Guitar Rig Loop Machine Data |
| ls2 | LabSat 2 Data |
| ls3 | Band-in-a-Box Third-Party Styles |
| ls3w | LabSat 3 Wideband Data |
| ls8 | LISREL 8 Syntax Data |
| lsa | Lightscape ASCII Data |
| lsb | Lightscape Binary Data |
| lsc | LOGO!Soft Comfort Circuit File |
| lsc | Light-O-Rama Schedule File |
| lsd | ABBYY Lingvo Dictionary User Dictionary |
| lsdx | Apex Z3 Lighthouse Secure Data |
| lse | Oracle Utilities Load Analysis Input |
| lsf | LISREL System Data |
| lsg | LimeSurvey Group Structure XML |
| lsi | SAP Business Objects Local Security Information File |
| lsim | LogicSim Circuit |
| lsl | LightScribe Label |
| lslibrary | LittleSnapper Library Package |
| lsn | MakeMusic Finale Lesson |