# MIT License The MIT License is one of the most permissive and widely used open source licenses, originating from the Massachusetts Institute of Technology in the late 1980s. Its brevity and simplicity make it a popular choice; the entire license is about 170 words. It allows virtually unlimited use, modification, and distribution, requiring only that the copyright notice and license text be preserved. The MIT License's permissiveness means code can be incorporated into proprietary software without obligation to release source code. This has made it the default choice for many JavaScript/npm packages, Ruby gems, and modern open source projects that prioritize adoption over ensuring derivatives remain open. ## The License Text (Summary) The MIT License grants permission to: - Use, copy, modify, merge, publish, distribute, sublicense, and sell - With one condition: include the copyright notice and license text ## Key Characteristics - **Permissive**: No copyleft, proprietary use allowed - **Simple**: ~170 words, easy to understand - **Compatible**: Works with almost all other licenses - **No patent grant**: Unlike [[Apache 2.0 License]] - **No warranty**: Software provided "as is" ## Notable MIT-Licensed Projects - **Node.js** - **React** - **Vue.js** - **Ruby on Rails** - **jQuery** - **VS Code** (source) - **Electron** ## MIT vs Other Permissive Licenses | Aspect | MIT | BSD | Apache 2.0 | |--------|-----|-----|------------| | Length | Very short | Short | Longer | | Patent grant | No | No | Yes | | Popularity | Highest | High | High | ## References - https://opensource.org/licenses/MIT - https://en.wikipedia.org/wiki/MIT_License ## Related - [[BSD License]] - [[Apache 2.0 License]] - [[GNU General Public License (GPL)]] - [[Functional Source License (FSL)]] - [[Open Source]] - [[Open Source Initiative (OSI)]]