Choosing to release a piece of software under the terms of a free software license is an important step through which many programmers and writers first approach the free software community. However, the myriad of licenses available can sometimes confuse and disorient the user, sometimes making this first step much harder than it should be. Let’s try and make things clearer.

Free software vs. standard copyright license

Suppose just for a single moment that you’re a student reading a Physics book which explains the Theory of Relativity. You are able to read the book, use the notorious formula E=mc^2 to solve all of your exercises and, if you’re a particularly brilliant student, perhaps even start from there to come up with a new formula leading to a new scientific discovery. In other words, the scientific knowledge is in the public domain, free for everybody to use, modify and redistribute — you don’t have to pay a royalty to Einstein’s nephew every time you solve a difficult physics exercise or you daydream about time-space travel.

Free software licenses are an attempt at making the world of technology closer to the world of science.

The world of technology, on the other hand, is largely dominated by patents, which makes it a “closed” and competitive model, in which knowledge is rarely shared without money being involved. Companies strive to patent their latest technological innovation and maximize their capitalization, as one might expect. Sadly this has a number of important consequences: the license with which a patented item is distributed to the public often prohibits reverse-engineering and, in general, any attempt at understanding the mechanism through which that piece of technology works.

In this sense, free software licenses may be regarded as an attempt at making the world of technology much more similar to that of science, particularly in the field of computer software. Every piece of software distributed with under a free license grants to everybody the rights to disassemble, rebuild, manipulate and personalize the product, making it possible to understand its inner mechanisms and adapt the product to the user’s needs.

There might be many reasons why you’d want to release your work with a free software license. First of all, as you may already know, the “free” in “free software” doesn’t stand for “free of charge”, but rather for granting others the freedom to modify and redistribute your work.

There is generally nothing preventing you from charging a fee for your product if you adopt a free license, apart from the cases where the license itself explicitly forbids you to do so. Since it is you, the original author, who can decide exactly which license to adopt, all you have to do is choose the license that best fits you and your specific needs, instead of just sticking with one — the standard copyright license — over which you have no control whatsoever.

You can get a feel for how software houses in recent decades have chosen to take full control over their distribution license by looking at this partial list of free software licenses on Wikipedia.

When small particulars can make huge differences: choosing the license that best suits your needs

A common point of confusion is the difference between the terms “Open source” and “Free software” license: although very similar in many respects, they are formally two separate movements. This is mainly because of historical reasons that resulted in characterizing the term “Open source” in a way that was somewhat different from its original meaning. You can read more about that in an interesting Richard Stallman article.

The beauty of free licenses lays in their extreme and unprecedented flexibility. A well-known example are the Creative Commons, which you can see adopted on an increasing number of popular websites. Creative Commons is not a single license, but rather a license suite that is designed to allow its users to pick and choose exactly which rights to grant and which ones to deny, therefore allowing a complete control over the legal terms associated with the work you’ll distribute.

Although very similar, the terms “Free Software” and “Open Source Software” are two separate movements, mainly for historical reasons