Must know not just about Software Licenses

We – Software professionals like everybody else down streets know that you need to have license to use licensed software, and you need not license to use open source software. Licensing was not an issue in majority of the Asian part of the world a two three years ago. However even that picture is ridiculously changing now. As project managers who travel across different geographies you must have to know precisely at least different type of license agreements and their respective legal obligations.  

One very confusing area is that terms free software and open source software are used interchangeably. I have borrowed following philosophies related from GNU. “In 1998, some of the people in the free software community began using the term “open source software” instead of “free software” to describe what they do. The term “open source” quickly became associated with a different approach, a different philosophy, different values, and even a different criterion for which licenses are acceptable. The Free Software movement and the Open Source movement are today separate movements with different views and goals, but may be they do work together on some practical projects”. Therefore I believe there is a propaganda based term clash between Open Source vs Free Software founders to demark their territories in the competitive landscape.

The TERM clash - Open Source vs Free Software

1. A free software license Definition

 : is a software license which grants recipients extensive rights to modify and redistribute, which would otherwise be prohibited by copyright law. To qualify as a free software license, the license must grant the rights described in The Free Software Definition or one of the similar definitions based on this.

2. An open-source license Definition

: is a copyright license for computer software that makes the source code available for everyone to use. This allows end users to review and modify the source code for their own customization and/or troubleshooting needs. Open-source licenses are also commonly free, allowing for modification, redistribution, and commercial use without having to pay the original author. Some open-source licenses only permit modification of the source code for personal use or only permit non-commercial redistribution. All such licenses usually have additional restrictions such as a requirement to preserve the name of the authors and a copyright statement within the code. One popular set of free open-source software licenses are those approved by the Open Source Initiative (OSI) based on their Open Source Definition (OSD).

What is important?

Therefore even provided the above definitions I too could not still find a clear difference between Open Source and free Software in terms of the purpose they stand unless otherwise the differentiation of the terms of license granting body. Let’s forget the craps for a moment and see what seriously we really have to know. I have heard, that starting in the early 2000s, number of companies began to publish a portion of their source code to claim they were open source, while keeping key parts closed. This led to the development of the now widely used terms free open-source software and commercial open-source software to distinguish between truly open and hybrid forms of open source. This is such a critical situation where as project managers we have to be careful and understand the legally obligated nature of the license. It says generally Free and open-source licenses generally fall under two categories: Those with the aim to have minimal requirements about how the software can be redistributed (permissive licenses), and those that aim to preserve the freedoms that is given to the users by ensuring that all subsequent users receives those rights (copyleft Licenses). I think this is the point where most writers and speakers deceive us. Knowingly or unknowingly they may be using the term Free Software for the Copyleft license and Open Source for the permissive license. Correct me if I am wrong. 

Copyleft license	Permissive license
Eg: GNU General Public License (GPL) Note: Any modifications made and redistributed by the end-user must include the source code for these, and the license of any derivative work must not put any additional restrictions beyond what GPL allows.	Eg: MIT license (Massachusetts Institute of Technology) BSD license (Berkeley Software Distribution) Note: Gives a user the permission to take the code and use it as part of closed-source software or software released under a proprietary software license.

Figure:  The distinction between Copyleft vs Permissive license

So in brief, the GPL license impacts "derivative works", but the MIT/BSD license does not.  This has huge implications.  If that too complicated - Let's take the following examples.

Code G is GPL licensed.  Code M is MIT licensed.  You wrote X.

You create project GX which contains your code (X) and G.  If you distribute GX (the source or binary) then you have to make GX available (this includes X -- your code -- which you might not have wanted to make available).  Why?  Because if GX is a derivative work, then GX is also licensed under GPL.

Note -- let's now say that someone takes your GX (since you published the source code) and makes GXY (by adding his Y code) -- now if he distributes that code (or binary), then GXY has be licensed under the GPL and the source code has to be made available.  This is a property that some people call "hereditary", other call "viral", and some prefer the pun "copyleft" -- which is the opposite of copyright. 

Let's now create MX which contains your code (X) and M.  If you distribute MX (code or binary) then you have to indicate that part of MX contains MIT licensed code.  But you don't have to say how much of it does, where it is used, how it is used.  You don't have to make X available.  And you can license MX any way you choose. You can license MX under MIT if you want, and publish it.  You can also license MX under GPL -- (you'd be licensing MX, but not altering the license of M -- since it's not your code to re-license).  You could also sell MX under a commercial license.

Note -- it would be pretty difficult to sell GX since anyone can get the source code from you -- so why would they buy it?  Moreover you cannot add any restrictions onto GPL licensed code -- so you cannot, say give it for free on the condition that someone donate a $1 to charity.  So in effect, if X is a valuable asset to you, creating GX (and distributing it to a 3rd party) just devaluated it.  This will cause some to be concerned about using GPL code if they deal with other code they value (e.g. have patents, secrets, etc.) 

Credits 

Google/Wikipedia

Charaka Danansooriya