Bootstrap is a free collection of tools for creating websites and web applications. It contains HTML and CSS-based design templates for typography, forms, buttons, navigation and other interface components, as well as optional JavaScript extensions. It is the No.1 project on GitHub with 65,000+ stars and 23,800 forks (as of March 2014) and has been used by NASA and MSNBC, among many others. Bootstrap was developed by Mark Otto and Jacob Thornton at Twitter as a framework to encourage consistency across internal tools. Before Bootstrap, various libraries were used for interface development, which led to inconsistencies and a high maintenance burden. In August, 2011 Twitter released Bootstrap as open source. In February 2012, it was the most popular GitHub development project. Bootstrap is compatible with the latest versions of all major browsers. It gracefully degrades when used on older browsers such as Internet Explorer 8. Since version 2.0 it also supports responsive design. This means the layout of web pages adjusts dynamically, taking into account the characteristics of the device used (desktop, tablet, mobile phone). Bootstrap is open source and available on GitHub. Developers are encouraged to participate in the project and make their own contributions to the platform. Recently, community members have translated Bootstrap's documentation into various languages, including Chinese, Spanish and Russian.