| ldd | Laser Dispatch Data File |
| lde | Veeam Explorer Exported Data |
| ldf | LDAP Data Interchange Format File |
| ldf | Lingoes Dictionary Source |
| ldf | LogPlot LogDesign File |
| ldf | Microsoft SQL Server Transaction Log |
| ldfx | LogPlot LogDesign XML File |
| ldg | TIBCO Business Studio Ledger Data |
| ldi | LDAP Data Interchange Format File |
| ldif | LDAP Data Interchange Format File |
| ldk | Larson Davis System 824 Firmware Authorization Data |
| ldl | Paradox Delivered Library |
| ldm | Sybase PowerDesigner Logical Data Model |
| ldmt | Likno Drop-Down Menu Trees Data |
| ldp | Active Directory Exported LDAP Data |
| ldp | Lingoes Dictionary Data |
| ldr | eSignal Hotlist Data |
| lds | VSE/VSAM Linear Data Set |
| ldsx | STAAD Advanced Concrete Design Cases and Combinations Data |
| ldt | EULUMDAT File |
| ldt | Oracle Generic Loader Data File |
| ldx | Lingoes Installed Dictionary Data |
| ldy | RAMAS Landscape Data |
| leases | DHCP Leases Database |
| led | AIBO LED File |
| lef | EnCase Logical Evidence Data |
| lef | LEN Exchange Format File |
| lei | Leica SP1 Image Session Data |
| lel | LayoutEditor Library Data |
| len | Esko PlatePrep Len File |
