| lo4 | Pervasive DataExchange Log |
| lo5 | Pervasive DataExchange Log |
| loa | MAXQDA Saved Formula |
| lob | IBM DB2 Large Object Data |
| lobs | HyperSQL Lobs Data |
| loc | TopoGrafix Location Data |
| local | Paket Local Data |
| localstorage | WebKit Local Storage Data |
| locs | Illumina BeadArray Location Data |
| locx | ARNColoc Custom Loc Data |
| lof | Audacity File List |
| logikcs | Apple Logic Key Command Data |
| logonxp | LogonStudio Windows XP Logon Screen |
| lol | CYANA Lower Distance Limit File |
| lon | Aquaterra Longitudinal Profile Data |
| look | Adobe SpeedGrade Look |
| loov | SmadAV Virus Definitions |
| lop | MasterCook Layout Data |
| lov | SAP Business Objects LOV File |
| lp | Lightscape Preparation File |
| lpa | LPA View Data |
| lpd | Helix Nuts and Bolts File |
| lpdb | Librarian Pro Database |
| lpl | LPL Model |
| lpm | WonderBit Life Photo Maker Data |
| lpmd | LPMD Molecular Data |
| lpn | LVPLAN Data |
| lps | Bryce 7 Leaf Shape |
| lpsx | LARSA 4D Section Database |
| lpv | Lasergraph DSP Laser Show Preview Data |
| lpw | IRIS Laserforms Lforms Data |
| lpx | LaTeXPiX Script |
| lqa | LabQuest 2 Automatic Update |
| lqf | LeechFTP Saved Queue |
| lqm | Liquid Audio Master Data |