A polyfill, also known as a shim, is a user-defined implementation of an API that some browsers provide natively, normalising browser differences.
# 1. They augment host objects
Polyfills augment host and native objects. Experts such as Richard Cornford, David Mark, Thomas Lahn and Kangax have told us this is a bad idea. The latter of which published two articles on the subject:
See original post