A set of Polymer elements, core of the Google Codelabs platform.
bower install is the obvious first thing to do.
To play with the demos, an easy thing would be to use
polyserve:
npm install -g polyserve.
Fire up the server with polyserve command and point your browser to:
https://localhost:8080/components/codelab-components/
Use web-component-tester to run tests.
Can be installed with npm install -g web-component-tester, or just fire up polyserve
and navigate to /components/codelab_components/test/<test-file>.