Skip to main content

What is the MIT License?

Top 10 questions about the MIT license answered

Escrito por:
0 minutos de leitura

What is the MIT License?

The MIT license gives express permission for users to reuse code for any purpose, sometimes even if code is part of proprietary software. As long as users include the original copy of the MIT license in their distribution, they can make changes or modifications to the code to suit their own needs.

It is one of the simplest open source license agreements. The intent was for the text to be understandable by average users and to avoid extensive litigation, which may arise from other similar Free and Open Source Software (FOSS) licenses

What is the history of the MIT license?

A joint project between IBM, MIT, and Digital Equipment Corporation (DEC) in 1983 seems to be the origin of the MIT license. The reason it only seems to be the start is that there were multiple different versions used at varying times with changes to the exact text.

Open-source software licensing became required in the 1980s. Before then, most programmers readily shared their code bases to improve scientific research and develop systems that could further human knowledge and technology. In the 1960s, computers had found applications in universities around the world, leading to researchers writing code to test their mathematical hypotheses.

At the Massachusetts Institute of Technology (MIT), the late Edward Lorenz first used his weather prediction software in the 1960s to note chaotic discrepancies when he introduced small changes to his simulations (now called Chaos Theory). These types of innovations made software highly desirable for large corporations, ushering in the era of proprietary software.

By 1980, source code for devices like printers was no longer freely available. It prompted MIT professor, Richard Stallman, to go on a lifelong crusade to make source code available to communities of developers. To keep software shareable, institutions, like MIT, were required to develop a software licensing agreement, especially for original code that originated from within the academic fields.

What are the benefits of the MIT Open Source license?

A significant benefit of using the MIT license is that it serves both sides of the debate equally well. Some developers feel the GNU GPL licenses are too liberal, while others think all software should eventually become proprietary. Due to the MIT License’s open language, it’s suitable for both community developers and teams that want to produce propriety software using existing pieces of MIT licensed code.

What are the MIT license terms and conditions?

The primary terms and conditions of the MIT license are to grant permissions and indemnify developers for future use. Specifically, it grants any person who obtains a copy of the software and associated files the right to use, copy, modify, merge, distribute, publish, sublicense, and sell copies of the software.

The only condition required to use the software is to include the same copyright notice in all copies or any substantial portions of the software. The final portion of the text provides for limitations and revokes any warranty implied by sharing the code.

What class is the MIT Open Source license referred to?

Open source and free software classes come in two distinct types.

  • Copyleft – Weak and strong copyleft(as opposed to copyright) licenses attempt to make all software based on any open source components also enforce similar FOSS licensing on their work.

  • BSD-Style and permissive – These licenses impose minimal restrictions (if any) on how any subsequent users can implement, modify, or extend the software for open source or proprietary purposes.

The MIT license falls under the permissive (or BSD-style) of FOSS licenses. BSD-style licenses allow any user to do anything with the code, granted they provide attribution and do not claim any liability in the future.

MIT License vs Apache 2.0

The Apache 2.0 license and MIT license are broadly similar, but there are some key differences. For one, the Apache 2.0 license text is much more thorough and contains more legal terminology than the MIT license. The MIT license aims to be the most simple and straightforward open source license for developers to distribute their software under.

Another key difference is that the Apache license requires developers to disclose any major changes they make to the original source code. The modified source code does not need to be revealed, but a notice of the modification is required. However, any unmodified code must retain the Apache license.

Unlike the MIT license, open source software under the Apache license that has been modified is permitted to be patented by the end user as well. These patent rights are global, perpetual, irrevocable, and non-exclusive as long as the modified version does not suggest that it’s endorsed by Apache in any way. The language of the Apache license makes the explicit grant of patent rights clear, but the patent rights are more ambiguous in the MIT license.

How do I get my MIT license?

To use the MIT license, developers need to copy the text as provided and include in source files as applicable. If using any other MIT licensed software in the project, retain the original license information at the top of the file, while keeping the copyright statements (if unchanged).

Can anyone use the MIT license?

Yes, any developer or user can include the MIT license in their project, granted they know that it means all rights associated with their work will be freely available for future modification.

Snyk offers an Open Source License Compliance Management solution that helps you maintain a rapid development pace while remaining compliant with the open source software licenses in your projects.

Can MIT-licensed code be used commercially?

MIT licenses allow commercial use. Users do not have to provide any other source code when releasing new software. Including the attributions and original MIT license in the reused code will suffice.

How popular is the MIT license?

Of all available FOSS licenses, the MIT license remains the most popular. In 2019, researchers found that 27% of all open-source licenses on Github were using the MIT license because it is short, to the point, and optimized for developers.

How do I know if I am compliant with license terms and conditions?

It is important to embrace license compliance early in the software development lifecycle. Snyk makes it easy for developers to integrate license compliance into their existing workflows. Offering a variety of integrations, Snyk enables developers to apply license testing on each and every stage of the SDLC as early as possible.

Solução da Snyk para conformidade com licenças

Snyk offers Git-based integrations (GitHub, Bitbucket, GitLab, CircleCI, TeamCity) to support license scanning as part of the regular workflow. New pull requests are scanned for license violations and indicate when a license check passes or fails in accordance with defined policies.