Code in ./common/lib/xmodule/xmodule should be imported as `from xmodule`, since `xmodule` is a locally-installed package. This is weird, but as long as it is the case, we should be consistent. (In BOM-2584, I propose moving the files to ./xmodule, which would quell this confusion.)
CMS (Content Management System) ------------------------------- This directory contains code relating to the course management portal for edX, also known as Studio.