Hello, I spent some time this morning struggling with out of date instructions on the main page under usage>cli on the site.
Correct instructions can be found at https://babeljs.io/blog/2015/10/31/setting-up-babel-6
It also needs to mention using a path to point to babel:
sudo ./node_modules/babel-cli/bin/babel.js --watch es6.js --out-file es5.js
Following the current instructions on the main cli usage page
produces error messages that do not point you in the right direction to fix them.