This project allows Node.js and browser applications to use any ES6-compatible Promise implementation, letting library authors support multiple Promise libraries without locking users into a specific one. It works by optionally registering a preferred Promise library (like Bluebird or Q) that will be used throughout the application, defaulting to the native Promise if none is registered. The tool is primarily for library developers who want to support various Promise implementations and for application developers who want to choose their preferred Promise library.