robust HTML entities encoder/decoder with full Unicode support

 _he_ (for “HTML entities”) is a robust HTML entity encoder/decoder written in
 JavaScript.
 .
 It supports all standardized named character references as per HTML, handles
 ambiguous ampersands and other edge cases just like a browser would, has an
 extensive test suite, and — contrary to many other JavaScript solutions — _he_
 handles astral Unicode symbols just fine.
 .
 Node.js is an event-based server-side JavaScript engine.