I. Overview
 
The MIT License originated from the Massachusetts Institute of Technology(MIT). It is also named as “the X License” or “the X11 License.” In realpractice, a variety of computer softwares have employed this license.
 
The MIT License is quite similar to the 3-clause BSD license.

 

II. Current Status

Many software projects, including Expat, Metakit, PuTTY, Mono development platform, and the X Window System (X11) have all employed the MIT License.

III. Rights and Duties

  1. Rights

The licensee is granted the permission to use the software without restriction, and the right to copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the software.

The licensee may modify the license accorrding to his/her needs on the programs.
 
  2. Duties
 
A copyright notice and this permission notice shall be included in all copies or substantial portions of the software.

IV. Other Important Features

  1. The MIT License is a non-copyleft free software license, which means it allows reuse among both free/open source and proprietary softwares.

  2. The MIT License can be modified to suit the particular needs of copyright holders. For example, the Free Software Foundation uses the MIT License for its ncurses library and add the following: ”Except as contained in this notice, the name(s) of the above copyright holders shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization”. This is also the essentially difference between the MIT and the BSD license (the 3-clause BSD license).

  3. The warranty clause is very simple.

  4. The MIT License may be dually licensed with other licenses.

  5. The MIT License is approved as a free software license by the Free Software Foundation and approved as an open source license by the Open Source Initiative  (OSI). It is compatiable with the GPL.