LO File

Files with .LO extension store compiled source code written in LISP for Interleaf software development environment. Compiled LSP files can hold commonly used routines and code fragments that can be accessed faster thanks to precompilation. Interleaf Compiled Lisp File uses I-Lisp syntax (a dialect of LISP). LO files are binary files and cannot be accessed or edited directly. Interleaf software tool was developed in the 1980s and sometime after acquired by BroadVision and further developed as QuickSilver.

Using LO files in Interleaf

I-Lisp along with compiled .LO files were used in Interleaf for customization purposes and to create automation scripts. Nowadays LO format is considered a legacy format as its specification is not included in QuickSilverdocumentation.