Currently available Software Licenses.

5 min readSep 8, 2020

First of all we should know what is “Software Licenses”. Wikipedia says that “A software license is a legal instrument governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both source code and object code forms, unless that software

was developed by the United States Government, in which case it cannot be copyrighted. Authors of copyrighted software can donate their software to the public domain, in which case it is also not covered by copyright and, as a result, cannot be licensed. A typical software license grants the licensee, typically an end-user, permission to use one or more copies of software in ways where such a use would otherwise potentially constitute copyright infringement of the software owner’s exclusive rights under copyright”. There are 5 main types of software licences and here some information about them.

Types of software licences :-

  1. Public domain.

This is the most permissive type of software license. When software is in the public domain, anyone can modify and use the software without any restrictions. But you should always make sure it’s secure before adding it to your own code base. Warning: Code that doesn’t have an explicit license is NOT automatically in the public domain. This includes code snippets you find on the internet.


Permissive licenses are also known as “Apache style” or “BSD style.” They contain minimal requirements about how the software can be modified or redistributed. This type of software license is perhaps the most popular license used with free and open source software. Aside from the Apache License and the BSD License, another common variant is the MIT License.


The GNU Lesser General Public License allows you to link to open source libraries in your software. If you simply compile or link an LGPL-licensed library with your own code, you can release your application under any license you want, even a proprietary license. But if you modify the library or copy parts of it into your code, you’ll have to release your application under similar terms as the LGPL.


Copyleft licenses are also known as reciprocal licenses or restrictive licenses. The most well-known example of a copyleft or reciprocal license is the GPL. These licenses allow you to modify the licensed code and distribute new works based on it, as long as you distribute any new works or adaptations under the same software license. For example, a component’s license might say the work is free to use and distribute for personal use only. So any derivative you create would also be limited to personal use only. (A derivative is any new software you develop that contains the component.)

The catch here is that the users of your software would also have the right to modify the code. Therefore, you’d have to make your own source code available. But of course, exposing your source code may not be in your best interests.


Of all types of software licenses, this is the most restrictive. The idea behind it is that all rights are reserved. It’s generally used for proprietary software where the work may not be modified or redistributed.

Under this type there are lots of software licences in the world like MIT, GPL,Apache etc. These are the result of research that done in 2016 about what are the software licences that mostly used in world.

  1. MIT, 25%
  2. GPL 3.0, 19%
  3. Apache 2.0, 15%
  4. GPL 2.0, 15%
  5. BSD 3, 6%
  6. LGPL 2.1, 6%
  7. Ms-Pl, 5%
  8. BSD 2, 3%
  9. Zlib, 1%
  10. Eclipse 1.0, 1%
  11. BSD 4, 1%
  12. Other, 5%

These are some information about some software licences.

MIT :- The MIT License is a permissive free software license originating at the Massachusetts Institute of Technology in the late 1980s. As a permissive license, it puts only very limited restriction on reuse and has, therefore, high license compatibility. It is compatible because it can be re-licensed under other licenses.

Apache :- The Apache License is a permissive free software license written by the Apache Software Foundation (ASF).[5] It allows users to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software under the terms of the license, without concern for royalties. The ASF and its projects release their software products under the Apache License. The license is also used by many non-ASF projects.

BSD licenses:- BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD license was used for its namesake, the Berkeley Software Distribution (BSD), a Unix-like operating system. The original version has since been revised, and its descendants are referred to as modified BSD licenses.

Eclipse Public License:- The Eclipse Public License (EPL) is a free and open source software license most notably used for the Eclipse IDE and other projects by the Eclipse Foundation. It replaces the Common Public License (CPL) and removes certain terms relating to litigations related to patents

I think you got some idea by reading this article. For more information these are the references that I used.




Undergraduate student of Software engineering-University of Kelaniya.