| lu | ThoughtWing Library Unit |
| luacodec | Reason Remote Lua Codec Data |
| luar | UltraDefrag Lua Report |
| lucidcolorset | Lucid Colorset Data |
| lucs | Amaya Tools Data |
| lucy | HTC Scribble Note |
| lud | ABBYY Lingvo Dictionary User Dictionary |
| lud | Altair FEKO LU-decomposition Data |
| lud | CARE-S InfoWorks Land Use Data |
| lue | Norton LiveUpdate Log |
| luh | ARINC 615A Load Upload Header |
| lum | DB-MAIN Binary Method Definition Data |
| lum | Luminous Schedule File |
| luminar | Luminar 4 Catalog Database |
| lunch | Lunchbox Battles Data |
| lup | ARINC 615A Load Upload Part |
| lup | OzWin Library Update File |
| lus | ARINC 615A Load Upload Status |
| lux | Spectramap Database |
| luz | Spectramap Data |
| lvc | Alstom MMS LVC Compiler Report |
| lvclass | LabVIEW Class Library |
| lvd | Avery LabelPro Design Document |
| lve | DanceScore Live Data |
| lvg | ListViewGenerator Data |
| lvix | Lightworks Index File |
| lvlib | LabVIEW Project Library |
| lvlibp | LabVIEW Packed Project Library |
| lvs | Daylon Leveller Selection Mask |
| lw | Lightwave 3D Binary Data |
| lw2 | Lightwright Show Data |
| lw3 | Lightwright Show Data |
| lw4 | Lightwright 4 Data |
| lw5 | Lightwright 5 Data |
| lwa | LightWorks Archive |
