The Node.js `util.deprecate()` function with browser support

A small polyfill for Object.setprototypeof

Fast (and loose) selective `process.env` replacer using js-tokens instead of an AST

Buffers events from a stream until you are ready to handle them.

process.nextTick but always with args

Use node's fs.realpath, but fall back to the JS implementation if the native one fails

Pass two numbers, get a regex-compatible source string for matching ranges. Validated against more than 2.78 million test assertions.

Safer Node.js Buffer API

Create a stream that emits events from multiple other streams

Merge multiple streams into one stream in sequence or parallel.

ES2015 `Object.assign()` ponyfill

Fast deep equal

A stream that emits multiple other streams one after another.

Returns true if a number or string value is a finite number. Useful for regex matches, parsing, user input, etc.

extend like a boss

[](https://travis-ci.org/stefanpenner/get-caller-file) [](https://ci.a

Normalize slashes in a file path to be posix/unix-like forward slashes. Also condenses repeat slashes to a single slash and removes and trailing slashes, unless disabled.

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

Support for representing 64-bit integers in JavaScript

Turn any collection of objects into its own efficient tree or linked list using Symbol