Early beginnings Bootstrap, originally named Twitter Blueprint, was developed by Mark Otto and Jacob Thornton at
Twitter in 2010 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. According to Otto: After a few months of development by a small group, many developers at Twitter began to contribute to the project as a part of Hack Week, a
hackathon-style week for the Twitter development team. It was renamed from Twitter Blueprint to Twitter Bootstrap and released as an open-source project on August 19, 2011. It has continued to be maintained by Otto, Thornton, a small group of core developers, and a large community of contributors.
Bootstrap 2 On January 31, 2012, Bootstrap 2 was released, which added built-in support for Glyphicons, several new components, as well as changes to many of the existing components. This version supports
responsive web design, meaning the layout of web pages adjusts dynamically, taking into account the characteristics of the device used (whether desktop, tablet, mobile phone). Shortly before the release of Bootstrap 2.1.2, Otto and Thornton left Twitter, but committed to continue to work on Bootstrap as an independent project.
Bootstrap 3 On August 19, 2013, Bootstrap 3 was released. It redesigned components to use
flat design and a
mobile first approach. Bootstrap 3 features new plugin system with
namespaced events. Bootstrap 3 dropped Internet Explorer 7 and Firefox 3.6 support, but there is an optional
polyfill for these browsers. Bootstrap 3 was also the first version released under the twbs organization on GitHub instead of the Twitter one.
Bootstrap 4 Otto announced Bootstrap 4 on October 29, 2014. The first alpha version of Bootstrap 4 was released on August 19, 2015. The first beta version was released on August 10, 2017. Otto suspended work on Bootstrap 3 on September 6, 2016, to free up time to work on Bootstrap 4. Bootstrap 4 was finalized on January 18, 2018. Significant changes include: • Major rewrite of the code • Replacing
Less with
Sass • Addition of Reboot, a collection of element-specific CSS changes in a single file, based on Normalize • Dropping support for
IE8,
IE9, and
iOS 6 •
CSS Flexible Box support • Adding navigation customization options • Adding responsive spacing and sizing utilities • Switching from the
pixels unit in CSS to
root ems • Increasing global font size from 14px to 16px for enhanced readability • Dropping the panel, thumbnail, pager, and well components • Dropping the Glyphicons icon font • Huge number of utility classes • Improved form styling, buttons, drop-down menus, media objects and image classes Bootstrap 4 supports the latest versions of
Google Chrome,
Firefox,
Internet Explorer,
Opera, and
Safari (except on Windows). It additionally supports back to
IE10 and the latest
Firefox Extended Support Release (ESR).
Bootstrap 5 Bootstrap 5 was officially released on May 5, 2021.
Major changes include: • New offcanvas menu component • Removing dependence on
jQuery in favor of vanilla JavaScript • Rewriting the grid to support responsive gutters and columns placed outside of rows • Migrating the documentation from
Jekyll to
Hugo • Dropping support for
Internet Explorer • Moving testing infrastructure from
QUnit to
Jasmine • Adding custom set of SVG icons • Adding CSS custom properties • Improved API • Enhanced grid system • Improved customizing docs • Updated forms • RTL support • Built in darkmode support == See also ==