With KiCAD 6 library file format was changed. This repo contains libraries in what is now legacy format. All newer stuff is hosted at https://github.com/rusefi/kicad6-libraries
This folder contains rusEFI libaries. These files are used by KICAD in circuit board layouts.
Please note that you would need to fork https://github.com/rusefi/kicad-libraries if you would like to contribute to rusEFI component library - you cannot contribute to this using https://github.com/rusefi/rusefi or other repositories
.lib schematic symbol (still usually multiple symbols in one file)
.kicad_mod PCB footprint in KiCad 4+ format (looks like usually one footprint in one file)
.mod - PCB footprint prior to KiCad 4 (could be multiple footprints in one file)
.net is technically not a true source file since it's produced from .sch schematics but InteractiveHtmlBOM likes to use these files as input. Open question how does InteractiveHtmlBOM use these .net files exactly?