proto
A prototype-based inheritance library that makes it easy to create objects and inheritance hierarchies without losing the power of javascript's prototype system.
base-classes
Useful JavaScript base classes for efficient and quick solutions to common problems.
java-class
Class.js is a Javascript library designed to allow easy, non-obtrusive creation of Java-like classes without requiring a cross-compiler, and without otherwise interfering with the capabilities of Javascript.
@specialblend/superclass
ES6 class mixin (multi class "inheritance") utility - easily extend ES6 classes from multiple classes