Copper vs Passport: What are the differences?
Copper: Password-free signups. No social network required. People sign up with their number. You get verified info. Copper is a service for developers who want a seamless, always-improving signup and signin flow in their websites and iOS apps. We remove friction so more people become and remain users, while makers ship faster and maintain less code; Passport: Simple, unobtrusive authentication for Node.js. It is authentication middleware for Node.js. Extremely flexible and modular, It can be unobtrusively dropped in to any Express-based web application. A comprehensive set of strategies support authentication using a username and password, Facebook, Twitter, and more.
Copper and Passport can be categorized as "User Management and Authentication" tools.
Passport is an open source tool with 15.9K GitHub stars and 936 GitHub forks. Here's a link to Passport's open source repository on GitHub.