Of course, this also means that there has to be a little bit more of research on your side in order to choose the license that works best for you. Yes, Creative Commons are very flexible, but some argue that while they are an excellent option for your articles and written content together with the GFDL, they are not the best to stick with if what you do is writing and redistributing software. Let’s then go over the features of the most common free licenses for source code.

GNU General Public license (GPL): by far the most common license in use for free software, mainly for historical reasons. A complete copy of the terms and conditions has to be included in every project that is being release with this license. In short, you can use the software for any purpose, change it to suit your needs, share it and any modified version you might produce. For a better explanation, see this guide.

BSD Licenses: considered more permissive than the standard GPL, BSD (Berkeley Software Distribution) licenses are the terms through which the common FreeBSD OS is being distributed. A software licensed under these terms allows developers of proprietary commercial tool to include it in their projects. What is maybe the most cited example of such behaviour was the inclusion of the FreeBSD kernel into Apple’s Mac OS X operating system.

If you want to grant anyone the right to use your work in whichever way they wish, release it into the public domain

Public Domain: if you want is to grant anyone the right to use your work in whichever way they wish, releasing it into the public domain is the way to go. By releasing your work into the public domain, you are effectively renouncing to your rights on it. Government agencies such as NASA and countless others will release pictures and other content in this manner. In most countries, the copyrights on someone’s work expire after a certain number of years — typically 70 to 100 — from the death of its author. These works then traditionally enter the public domain.

When looking at the myriad of licenses, all promoting the exact same philosophy in just a slightly different manner, one does however wonder whether it would be best to have a single “unified” license for free software, or at least a bit more of flexibility from project managers in choosing a license that would be compatible with the vast majority of the ones that share the same basic principles.

Needless to say, this is far from happening any time soon. You really don’t have to search far to hear about disputes, incompatibilities and legal controversies that originated from the misuse or misinterpretation of the license terms even within the free software community.

A case study: Logo issues between Mozilla Firefox and Debian Linux

The controversy between Mozilla Firefox and Debian Linux is certainly a textbook example of an outstanding issue that originated from small particulars to evolve into somewhat drastic decisions.

Mozilla Firefox, quite possibly the best-known free software application in existance, isn’t released under either of the two most common free software licenses such as the GNU General Public License (GPL) or the more permissive BSD license, but rather an hybrid of the two.

In short, the resulting Mozilla Public License (MPL) allows modifications of the software, as long as the resulting software is being distributed under a different name and featuring a different logo.

The reason behind the adoption of the MPL was the need for Mozilla Corporation to protect the very solid reputation of the software. Imagine what would happen if a popular, but unofficial fork of “Mozilla Firefox” was extremely buggy: what the common user would perceive is that the entire project was unstable and of poor quality.

The reason behind the adoption of the MPL was the need for Mozilla Corporation to protect the reputation of its products

Debian Linux — the popular GNU/Linux distribution which is known to put great attention to the licensing terms of its packages as well as their stability — was initially given permission to use the Mozilla trademark and to adopt the “Firefox” name even with customized, non-proprietary artwork specific for the distribution.

In February 2006, however, the Mozilla Corporation decided to revoke the trademark agreement due to what the corporation interpreted as misuse of the “Firefox” name.

As a result of a long dispute, Debian Linux eventually decided to abandon the former Firefox branding, opting for the name “Iceweasel” instead, as a reference to an earlier GNU project.

Ending on a positive note: GNU’s GFDL and CC

On December 1, 2007, Jimmy Wales, the co-founder of the Wikipedia project, announced that, after a period of negotiation among the Free Software Foundation, Creative Commons and the Wikimedia Foundation have produced the proposal to modify the Free Documentation License — maybe the best known license for free documentation — in such a way that it would be compatible to the CC-BY-SA (Creative Commons with Attribution and Share-Alike rights).

This is certainly a positive note, as GFDL and Creative Commons are undoubtedly two of the most widespread documentation licenses in use today, and knowing that the two are on the road to resolve their differences to embrace the spirit of free software will certainly leave the free software community stronger.

The large number of free software licenses available clearly reflects the different needs of users and certainly each license has its own raison d’être. However it is possible that the free software community will see more similar attempts at working together towards cross-compatibility. In this way they’ll put the legal nitty-gritty aside and make the software reuse, modification and redistribution process much easier to implement.`