Understanding open-source and free software

In order to fully appreciate the value of open-source software, it's important to understand its meaning in entirety

Saturday, March 01, 2008

There are lots of myths and realities about open-source and free software that cause lots of confusion. Is open-source really free or vice versa? If so, then why do so many vendors claim to sell open-source software, and yet attach a price tag to their products? Does open-source mean Linux, and is Linux a free OS? If this is true, then both open-source and Linux should be free. The fact of the matter is that none of these statements are necessarily true. As if all this wasn't enough, add to it the plethora of different licensing terms and what you get is a big bag of confusion. So let's clear the air a little and separate myths from realities.

What does 'free' sw really mean?
Let's first define free and then move to its relation to Open-source. The word 'free' has two meanings. One is free software, or freeware that somebody creates and distributes unconditionally. There are no license agreements, the software is distributed as is, and the owner takes no responsibility whatsoever if the software does something unwarranted to your system(s). You're on your own if your system crashes.

The other definition of free software has been created by the FSF or Free Software Foundation (www.fsf.org). The FSF was formed by Richard Stallman, the founder of GNU software and the famous GNU General Public License (GPL). The FSF has its own definition of free software. In this definition, free does not mean 'no cost'. It's free as in freedom or liberty to run, modify, distribute, or improve the software. Needless to say that access to the program's source code is a must to fulfill at least three of these needs.

GNU software and GPLed software come under this 'free' software definition, i.e. you have the right to run it for your own requirements, modify its source code to suite your needs, distribute it for free or even sell it. But when you do modify and distribute it, you can't put any restrictions that will negate any of the conditions in FSF's definition of free software. For instance, you must distribute the source code along with the program as a part of the agreement. But if you put restrictions, it violates the license agreement.

What's open-source then?
Let's now move on to open-source software. This is the same as free software of FSF, but it comes under the banner of the Open Source Initiative (www.opensource.org), which is another independent group that's involved in open-source community building and educating. The OSI has its own 10-point definition for open-source software. This definition also has many of the things in the 'free' software's definition, like free redistribution, access to source code, modifications, etc.

The interesting thing is that both FSF and OSI are committed to achieving the same objective-that of giving everyone the right to run, modify, distribute or improve software. However, their philosophies towards achieving the goal differ. We'll not get into those in this story. What's important to understand is that both organizations help software developers create licenses that are compatible to their definitions. This is a very important task because there are tons of licenses out there in the open-source world, which make the definition of open-source and its implications extremely confusing.

Everybody makes their own claims and put in their own restrictions. To ease the process, both FSF and OSI have put up lists of software licenses that are approved by them, i.e. they're in accordance with their definitions. In fact, there are many licenses that overlap across both as well.

Can I sell open-source or free software?
Yes, neither of the two types of software put any restrictions on commercialization. In fact, there's a dual-licensing model that's gained popularity, which allows you to distribute two different versions of the same software, one for free community distribution and improvements, and the other as a commercial package. There's a separate article on dual-licensing to explain this more clearly.

Where does Linux fit into all this?
Linux was first made available in the open-source world under the GNU General Public License. The OS was distributed freely along with the source code, and has never looked back since then. Since it was an open-source Operating System, other communities made use of it and brought out their own versions. Such versions are called Linux distros. We've all heard of Linux distros like RedHat, Suse, Debian, CentOS, etc. In face, the PCQ Linux 2008 bundled with this issue is also a distro. Some of these distros are freely available and usable, while others are commercial. RedHat for instance, has a community version called Fedora, and the commercial version is known as RedHat Linux. Likewise, Suse has a community edition called openSUSE and a commercial SUSE.

But just because Linux is open-source doesn't mean that vice versa is also correct. Open-source doesn't necessarily mean Linux. Today, you'll find lots of open-source software that run on Windows and other platforms. Many popular applications that were available on Linux have also been ported to Windows. Apache, Perl, MySQL, are just a few well-known open-source apps available for both Linux and Windows.

Types of Licenses
Before using any open-source software, it's important to see what type of license agreement it has adopted. There are so many licenses that their explanation would fill up this entire story. Basically, just about every major open-source community out there has released their own license, e.g. Apache Software License, Mozilla Public License, Eclipse Public License, and so on. There are also commercial entities who've also released their licenses in the public, e.g. a Microsoft Public License, Lucent Public License, etc.

A few popular licenses include GNU GPL, GNU Lesser GPL, Apache Software License, Mozilla, and Eclipse. The GNU GPL is the most popular license in the open-source world. The license is now in its 3rd revision. A word of caution here though is that different open-source software are based on different versions of the GPL. So you'll still find software based on the first and second versions of GPL. Another important thing to remember about GPL and similar licenses is that if you go ahead and use some GPL code in your application, you need to release its source code as well – whether you want to or not. Many people use FSF/OSI applications only because they feel they are “cheaper”. But very few actually change the applications's code itself, for e.g. tons of web sites are done on PHP, but probably less than 1% would have ever changed the source code of PHP itself. Incidentally, even commercial companies are giving out their source under their own licenses. A very good and important example is the Microsoft .NET Framework. The entire source code is now available for you to download and view.

lastly, it's important that before you use any open-source software, read its software license agreement. The thing to remember is that even if an open-source software itself is available free of cost, you'll still end up paying for its support. Depending upon the mission criticality of its usage, you'll choose an appropriate agency for it. If it's for simple, internal use, you might even go for inhouse manpower to support it, whereas if you use it for your offices across the globe, then you'll need an agency that can provide you such level of support.

This was just a broad overview on open-source and free software and the various license policies. It should by no means be considered as legal advice. If you need legal advice on open-source and free software licensing, then please consult a lawyer.

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