Research Responsive Design Framework

Identify the framework your researched.
The framework I chose to research was Bootstrap.
Who wrote or supports the framework?
Bootstrap, originally named Twitter Blueprint, was developed by Mark Otto and Jacob Thornton at Twitter as a framework to encourage consistency across internal tools. Bootstrap is maintained by the founding team and a small group of invaluable core contributors, with the massive support and involvement of our community.
List some companies or organizations using this framework.
NBA.com
Indeed.com
Walmart.com
target.com
bloomberg.com
Briefly describe the framework and its primary features.
Bootstrap is a free and open-source front-end library for designing websites and web applications. Some of the features are:
Responsive Features
Mobile-Friendly
Base Styling for most HTML Elements
Great Grid System
What are some of the advantages/disadvantages to using this framework?
Pros:
Easy to get started
Great grid system
Base styling for most HTML elements
Extensive list of components
Cons:
The developed content can lack uniquness.
Non-compliant HTML
Styles are verbose and can lead to lots of output in HTML which is not needed.
What are some of the primary features or pre-built functions of this framework?
Bootstrap Themes
Bootstrap CSS references
Bootstrap Grids
Bootstrap JavaScript references
Bootstrap Components