Get and robustly cache all JS language-level intrinsics at first require time

Implementation of Function.prototype.bind

Robustly `.call.bind()` a function

string representations of objects in node and the browser

Determine if the JS environment has Symbol support. Supports spec, or shams.

Store information about any JS value in a side channel. Uses WeakMap if available.

Does the environment have full property descriptor support? Handles IE 8's broken defineProperty/gOPD.

ECMAScript spec abstract operations.

Define multiple non-enumerable properties at once. Uses `Object.defineProperty` when available; falls back to standard assignment in older engines.

Is this JS value callable? Works with Functions and GeneratorFunctions, despite ES6 @@toStringTag.

ES6 spec-compliant Object.assign shim. From https://github.com/es-shims/es6-shim

Determine if the JS environment has `Symbol.toStringTag` support. Supports spec, or shams.

Node's event emitter for all engines.

Which kind of Typed Array is this JavaScript value? Works cross-realm, without `instanceof`, and despite Symbol.toStringTag.

An Object.keys replacement, in case Object.keys is not available. From https://github.com/es-shims/es5-shim

ES6 spec-compliant RegExp.prototype.flags shim.

Standard library

Is this value a JS Typed Array? This module works cross-realm/iframe, does not depend on `instanceof` or mutable properties, and despite ES6 Symbol.toStringTag.

Is this value a JS regex? Works cross-realm/iframe, and despite ES6 @@toStringTag

Returns an array of Typed Array names that are available in the current environment

Is this value a JS Date object? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Is this value a JS SharedArrayBuffer?

Is this value a JS String object or primitive? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Determine if the JS environment has BigInt support.

A better forEach

Is this value a JS Number object? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Is this value a JS Boolean? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Does this JS environment support the `name` property on functions?

Which kind of boxed JS primitive is this?

Object.prototype.hasOwnProperty.call shortcut

Is this an arguments object? It's a harder question than you think.

node's assert.deepEqual algorithm

ES2015-compliant shim for Object.is - differentiates between -0 and +0

Is this value a JS Set? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Is this value a JS Map? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Get an iterator for any JS language value. Works robustly across all environments, all versions.

Node's querystring module for all engines. (ES3 compat fork)

Selectors for Redux.

Fast 3kb React-compatible Virtual DOM library.