Meteor.js is a full-stack JavaScript platform that simplifies web application development by allowing developers to use a single codebase for both the client and server sides. It provides an integrated set of technologies, including real-time data updates, a reactive templating engine, and a built-in package management system, streamlining the process of building modern and scalable web applications.
Grunt is a popular JavaScript task runner that automates repetitive tasks like minification, compilation, and testing, allowing developers to focus on writing code.