[galaxy-dev] any introduce for how Mako and JavaScript work in galaxy?

Hi everyone, I want to make some change for my local galaxy web, actually I can edit galaxy_path/static/scripts/bundled/*.js directly. It seems mako templates are used for galaxy, as well as many JavaScript files, but I don't know how they work. So is there any introduce for how mako and JavaScript files working in galaxy? Thank you very much. Steven