This directory is intended for the project specific (private) libraries. The source code of each library should be placed in separate directory, like "lib/private_lib/[here are source files]". For example, see how can be organized `Foo` and `Bar` libraries: |--lib | |--Bar | | |--docs | | |--examples | | |--src | | |- Bar.c | | |- Bar.h | |--Foo | | |- Foo.c | | |- Foo.h | |- readme.txt --> THIS FILE |--src |- main.c Then in `src/main.c` you should use: #include #include // rest H/C/CPP code