I've googled for Ubuntu source code, got on their GitHub and unfortunately didn't find it. I'm looking for a source code that can be built/compiled as ISO and what are the requirements to do so.
This is a related question Where can I find the source code of Ubuntu?, which is outdated now.
Why I want the source code? So that I can modify how the OS behaves in some way (like drag-n-drop in taskbar, customize the start menu etc.). Where can I find it?
