Tools
This directory is best browsed while listening to https://www.youtube.com/watch?v=hglVqACd1C8.
Protect Babel
The protect script seen here is to throw errors if someone ever tries to include internal babel files in their script. If you need something to be exposed, you should ask for it, not try to hack your way into getting it.
External Helpers
You'll also find the script for building the external helpers file, this is the Babel "runtime" where all helper functions go instead of the top of a file.