What's proposed as the "modular" approach is close to what I use, perhaps with the following modifications: 1. instead of folders for sub-systems at the top le

What's proposed as the "modular" approach is close to what I use, perhaps with the following modifications: 1. instead of folders for sub-systems at the top level, put them all into src/. 2. I use the name ext/ instead of lib/ for external libraries, because in POSIX, the lib/ name indicates where the binaries of static and dynamic/shared libraries reside (not their sources). I use a simple sh script called mkprj <project-name> to create that folder hierarchy for a new project.