Earlier quoted context omitted.
There was (and is) no reason for it to exist since python supports running .zip files that contain all the dependencies.
I had never heard of that, reading up on it now. Thanks for posting!
Re: Pip.wtf: Inline dependencies for small Python scripts
#11pex is a build tool built on the top of the zip trick. A pex file doesn't contain a bundled interpreter, but it zips up the entire virtualenv. Also no Windows support.