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What are the top 5 least restrictive Software Licenses?

What are the top 5 least restrictive Software Licenses

A software license is a legal document that guides software users on how to use and distribute software without violating ownership, distribution and control rights. The least restrictive software licenses allow users more liberty and rights to control, use and distribute software.

Being a software developer, I have used several open sources of software. I understand that the software has different types of licenses; some have a high restriction and others have the least restriction. Understanding the level of restriction on a software license is crucial to avoiding the risks of legal actions. In this post, you will learn the five least restrictive software licenses. The significant difference between the licenses is in the wording. Some are more explicit than others.

MIT License

Under this license, you are permitted to use, modify, sell, publish, sublicense and distribute the code of the software. However, individuals who use the code must include the original copyright notice. The aim is to enhance learning, scientific research and technological growth. The MIT licenses help individuals and teams that want to benefit the community through coding to have an easy start. It is a low-risk license.

Apache License

This license grants you the right in patent and copyright terms. This license permits you to copy, modify, publish and distribute the source code. The rights given to the users are irrevocable and apply to every country across the globe. No fee is charged for the rights, and everyone can use them. However, you are required to maintain the same license when you distribute, sell, and modify. Additionally, you are required to acknowledge the original author. Using software under this license has low legal risks.

The 3-Clause BSD License

In this license, you can use and redistribute the source code or its modified and binary forms. However, users are required to meet the following conditions

  1. When redistributing the binary form, the original copyright notice must be included, the list of redistribution conditions and all the materials provided with the original distribution.
  2. The user must not promote or endorse products obtained through the software using the names of the contributors or the copyright holders.
  3. Any form of source code redistribution must include the three conditions listed here and the copyright notice.

The license is considered a low-risk license.

ISC license

Under this license, you have the permission to distribute, modify, copy and or use the software for any reason without paying any fee. Users must, however, ensure that any usage includes the license copyright notice and conditions of use. Therefore, you must make any software modifications available to others and permit them to use, modify, copy and redistribute.

Code project open license

Under this license, you can use the source code in your application, modify the source code to a better version suitable for your use, and distribute the code for any reason, including commercial purposes. However, you must include a copy of the license in all copies and state the condition of use as stated in the original copy.

The table below is a summary of the top 5 least restrictive Software Licenses

Software Licenses Usage
MIT License Very wide
Apache License Very wide
The 3-Clause BSD License Wide
ISC license rare
Code project open license rare


Less restrictive software licenses have shallow legal risk. When considering using software for various purposes, always consider the type of licenses they are provided.


Can I use the software under the licenses for commercial purposes?

Yes. You must, however, ensure that those purchasing have access to the license and the conditions listed under the license.

Can I change some aspects of the license when I modify the software?

No, you cannot change any part of the license even when you have modified the software.