In the field of software today, one cannot avoid the term "Open Source". You may also have come across the phrase "Free Software", and you may think that the two are synonymous. But they aren't.

Free Software a political movement - just as one might campaign for freedom of speech or freedom of the press, the Free Software Movement believes that everyone should have the right to study, modify, and share the software they use. They call software for which such rights are available "free". But, in English at least, the term is handicapped by an ambiguity problem. "Free" can also, and more often does mean "zero cost", so when someone speaks of "free software" a listener might misunderstand them.

Open Source was originally coined as a marketing programme for free software - a way to surmount this ambiguity barrier. But it was later taken up by members of the community who did not agree with the political message of the Free Software movement and wanted to disassociate themselves from it. Their motivation for writing code using the same public development methodology was that they thought it made for better software than the proprietary way - pragmatism rather than principle.

The Open Source term has been a great success - its unambiguous nature has appealed to journalists who want to avoid terminological confusion when writing about the community's recent achievements, such as the Firefox web browser or the Open Office.org office suite. However, the change of phrase, combined with the apolitical stance of some sections of the community, has resulted in a loss of focus on the freedoms that Free Software stands for.

And if you do not understand and value a freedom, it's very easy to lose it, or for someone to persuade you to give it up. You probably will not even notice it's gone until you need it and suddenly find it's not there. The pragmatic "use what's best" approach of Open Source leads to the conclusion that if another program is better, you should use it, even if it's not Open Source. So if Skype is the best software for making telephone calls over the net, you should choose it; after all, it's "free" - it costs nothing - right?

So why should you care? If you are not a programmer, you cannot study or modify the software you use. At first sight, you appear to be at the mercy of your software supplier, whether the software is proprietary or free. If you want to redistribute it to your friends, generally zero-cost is all that's required.

But failing to choose freedom can affect you in serious ways. All the users of a popular zero-cost but proprietary e-mail program called Mulberry were abandoned this week, when the company which owned the software went bankrupt. The code is now owned by the liquidators, and the users are in the drink. They did not value their freedom enough to choose Free Software, and now they are missing it.

On the positive side, choosing freedom has great benefits. The Firefox web browser has more than 650 extensions available, which add abilities ranging from blocking ads to keeping a close eye on your Gmail inbox.

In large part, the size and health of the extension community is due to the fact that Firefox is free software - not only can the extension makers examine it carefully to see how best to integrate with it, they can get changes made to make their extensions work even better. And users benefit from this because those hundreds of abilities are there for them to install and use, even if they have never written a line of code in their lives.

So seek out and use free software (even if, at the moment, you are using it on top of a proprietary operating system), understand and cherish the freedoms it gives you and the benefits you get from that, and do not let any one take them away.

Gervase Markham works for the Mozilla Foundation, a non-profit organisation dedicated to promoting choice and innovation on the Internet. His blog is Hacking for Christ

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