The Open Source Initiative lists 9 different licenses in their list of "License that are popular and widely used or with strong communities".

I want to license my project as open-source. Unfortunately, I do not speak legalese. Is there some chart I could consult that will help me make the right choice, or at least point me in the right direction? For example a table summarizing the differences between the licenses, or perhaps a flow-graph using my requirements to guide me into the correct license for me?

I also intend to meet a lawyer, but any information to start with will help.


4 Answers 4


Jeff Atwood has done a pretty good job explaining the differences among the multitude of Open Source software licenses in plain English here:


The most important consideration affecting your decision will be your redistribution terms. That is, will you allow your code to be used in commercial applications and if so, will you require such applications to open-source their own code?

This is where the GPL is notable: If you license your code under the GPL, anyone using your code must also license their code under the GPL. Since the GPL requires that all of your code be open-source, this pretty much excludes its use in companies that wish to keep their code proprietary.

Note that the GPL does allow you to use GPL'd code for in-house business applications, so long as you do not redistribute those applications to a third party.

See Also

  • 4
    Jeff's advice has some errors in it! In many jurisdictions you can not put your work into the public domain (other than by being dead for the requisite amount of time) and it also doesn't mention your point about GPL for code you don't release, for which I'd mention server code, which is a very important model in the industry
    – jk.
    Commented May 6, 2012 at 7:46

As you have asked for a chart of Open source licenses comparison:
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Please, read this excellent article too: Adopting an Open Source Approach to Software Development, Distribution, and Licensing.


A great resource for understanding open source licenses is the very comprehensive, interactive license differentiator, from Oxford Universities OSS Watch.

This asks questions which guide you towards a suitable license for your software.

There are pro's and cons to each, so read up on what restrictions they place on the code and decide who you want to be able to use it. Warning, whichever you choose someone will complain - this is holy war territory, and beyond the scope of this question.


There's a simplified explanation for many licenses available on NRecursions (there are more licenses on the blog. Listed a few below).

  • Copyleft license: You can use, modify and distribute the license under the same or equivalent license, but you should also share the source code.
  • Berkely Software Distribution license (BSD): You can combine the software with your proprietary software and release it under a proprietary license, but you have to retain the BSD license text and notices. This license may also have one or two more clauses about using the author's name or advertising.
  • Gnu Public License (GPL): You can use, modify and distribute the software for free or for a fee, but you have to also distribute the source code with it, and if the software is combined with other software, that software will also have to be released as GPL, unless it is not an aggregate (it does not interact with the GPL software)
  • Lesser Gnu Public License (LGPL): Same as GPL, but you're allowed to link your proprietary software with LGPL software and release it under your terms. But there are some conditions under which you can do so.
  • Affero Gnu Public License (AGPL): Same as GPL, but it additionally says that your software is considered as having been distributed, if someone else is able to use it (like if you keep it on a server and they can run it from the server).
  • Massachusetts Institute of Technology license (MIT): You are allowed to use, modify and distribute copies of the software as long as you allow the same rights to the person to whom you distribute the software
  • Apache License: If you follow the Apache license, you're allowed to use, modify and distribute copies of the software, and you can add your own copyright statement to the changes you make. You can also provide additional or different license terms and conditions for use, reproduction or distribution of your modifications.
  • Mozilla Public License (MPL): You can use, modify, distribute and sell the software, provided you also give the recipient the source code. You can also sub-license the modified work, provided you don't restrict the recipients rights to the source code.

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