Toptal

If you’re doing anything web related, chances are you’ve heard about Bootstrap. Bootstrap is a powerful toolkit – a collection of HTML, CSS, and JavaScript tools for creating and building web pages and web applications. It is a free and open source project, hosted on GitHub, and originally created by (and for) Twitter. If by now you still don’t know what Bootstrap is, or you just want to get a better overview of what it is and what it does best, you’ve come to the right place.

Source: Toptal