Array#isArray for older browsers

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.

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.

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

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.

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

ES spec-like internal slots

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

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

ECMAScript “ToPrimitive” algorithm. Provides ES5 and ES2015 versions.

An ES2015 spec-compliant `Function.prototype.name` shim

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

ES2017 spec-compliant Object.values shim.

An ES7/ES2016 spec-compliant `Array.prototype.includes` shim/polyfill/replacement that works as far down as ES3.

ECMAScript spec-compliant polyfill/shim for `globalThis`

Object.prototype.hasOwnProperty.call shortcut

An ES2019 spec-compliant `Array.prototype.flat` shim/polyfill/replacement that works as far down as ES3.

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

ES proposal-spec-compliant Object.fromEntries shim.

ES2017 spec-compliant Object.entries shim.

Implements performance.now (based on process.hrtime).

Spec-compliant polyfill for String.prototype.matchAll

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.

ES2017 spec-compliant shim for `Object.getOwnPropertyDescriptors` that works in ES5.

Utility package to determine if an `Array.prototype` method properly boxes the callback's receiver and third argument.

requestAnimationFrame polyfill for node and the browser

A kickass library to manage your poppers

ES2017 spec-compliant String.prototype.padEnd shim.

Configuration and scripts for Create React App.

An ES5 spec-compliant `Array.prototype.map` shim/polyfill/replacement that works as far down as ES3.

Iterate any JS iterator. Works robustly in all environments, all versions.

ES Proposal spec-compliant shim for Promise.allSettled

A lib for generating Style Sheets with JavaScript.

ES Proposal spec-compliant shim for Promise.prototype.finally

ES2017 spec-compliant String.prototype.padStart shim.

Smooth Scroll behavior polyfill

Polyfill/shim for `document.contains`

High performance (jankfree) lazy loader for images (including responsive images), iframes and scripts (widgets).

Glide.js is a dependency-free JavaScript ES6 slider and carousel. It’s lightweight, flexible and fast. Designed to slide. No less, no more

JavaScript object inheritance sugar: Easy extension, mixins, super methods, proxies

Give your page some headroom. Hide your header until you need it

A library to edit lottie-web animations dynamically

Get notified when a DOM element enters or exits the viewport.