GPL-Virus Or Vaccine

A common refrain that I keep hearing on the mailing lists and the websites is how the GNU General Public License (, henceforth referred to as GPL, is viral. Microsoft, SCO and clueless marketing drones have added their share of fuel to this smear campaign, making companies and managers wary of choosing GPL licensed products. A virus is a parasitic microorganism that can make humans or computers sick; comparing anything with a virus is a nasty accusation. Usually the accusers provide no justifications on why has not tried to justify this accusation. Let us therefore try to investigate whether the GPL is really like a virus.

First, let me cover what GPL allows you to do. GPL is what we call a free software license. This means that you are allowed use, copy, and distribute (with or without making any modifications) the software without breaking any contractual agreement(1) You can charge a fee for redistributing software, or do this free of charge.

GPL gives you more power and choices than any proprietary software license. So why are people complaining ? The reason for the hue and cry is the section 2b. of the GPL, reprinted here

You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.

This brings me to what you are not allowed to do. If you release the modified version (of the original software that you got) to the public in some way, the GPL requires that you must also allow the users (of your modified software) to use, copy, modify and redistribute the software too. This means that you give recipients all the rights that you have. In simpler terms, you cannot add more restrictions when you redistribute GPL-covered software. You must pass along all the freedom that you originally received.

TODO GPL distractors use this point to smear GPL. The GPL does not require you to release your modified version. You are free to make modifications and use them privately, without ever releasing them.You are allowed to sell copies of the modified program commercially, but only under the terms of the GPL. TODO

Let us examine if GPL can be described as a virus. GPL does not forces itself over anyone. Whoever wishes to copy parts of GPL covered software into his program must let others have the same freedom that he received. This is a fair bargain. If it was permissible to incorporate GPL-covered software into a non-free system, it would have the effect of making the GPL-covered software non-free too. You should not subtract from the freedom you get when redistributing software. GPL is not restrictive. It meremly insists that whoever takes from the common pool must contribute back to the pool. The term Potentially Viral is a is entirely wrong when applied to GPL.

Let us now examine whether we can describe GPLas a vaccine. GPL protects the abuse of your code by having someone take your hard work and incorporating it into a proprietary product. If you are a developer GPL protects you from others who would like to take control of your software. You can avoid the risk of having to compete with a proprietary modified version of your own work. If you are a user you get the freedom to use, copy and distribute the software without having worry about any legal hassles.

Let us hold the mirror up to Microsoft(2) and examine their End User License Agreement (EULA) instead ( From the Mobile Internet Toolkit EULA).

Microsoft grants you a personal, nonexclusive, royalty-free license to install and use the Software for design, development, and testing purposes. You may install and use the Software on an unlimited number of computers so long as you are the only individual using the Software.
This effectively curtails the freedom of the user to copy the software.

A little further, in the section SOFTWARE TRANSFER from the same EULA

The initial user of the Software may make a one-time permanent transfer of this EULA and Software to another end user, provided the initial user retains no copies of the Software. The transfer may not be an indirect transfer, such as a consignment.
This takes away the freedom to redistribute the software (which they have purchased). The whole EULA is an attempt to take freedom away from the users. Almost every proprietary software's EULA is a variation of this theme.

How come when Microsoft's EULA is so restrictive that it calls GPL viral? It cannot dismissed as an arbitary whim or misunderstanding. The defining characteristic of a virus is is harmful nature. Microsoft's EULA is more harmful than GPL(which cannot be said to be harmful to anyone). This is a smear tactics. It is not only a negative connotation, it is entirely wrong. The GPL is not a virus, it is a vaccine. If you are a progrmmer ,GPL is an innoculation against abuse of your code. if you are an user, it is an innoculation against abuse of your freedom.



The Free Software Definition gives a more comprehensive treatment to what qualifies as Free Software.


Most proprietary softwares are licensed under almost similar conditions, Microsoft s just an easy example

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