12 Part I Linux Basics

Understanding Open Source

1.5 Compare and contrast how major Linux licensing schemes work (e.g., GNU/GPL, freeware, shareware, open source, closed source, artistic license)

The GNU GPL makes Linux Open Source because it is an acceptable license for Open Source Software. Open Source follows a similar path of the GNU GPL, but it also has many differences. Even though the Open Source Initiative strictly adheres to GNU GPL, it is not a specific license; rather, the Open Source Initiative supports the various types of open source licenses that are available. The idea behind the Open Source Initiative (OSI) is to gather corporate support behind open source. Companies that want to participate in Open Source are allowed to write their own license or use the GNU GPL and submit the license to the OSI for certification. This opens the door for all Open Source software and guarantees not only source code access but also follows the Open Source Definition. Full information on the Open Source Initiative can be found at www.opensource.org. The Open Source Definition is as follows:

Free Distribution — The license shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license shall not require a royalty or other fee for such sale.

Source Code — The program must include source code, and must allow distribution in source code as well as compiled form. Where some form of a product is not distributed with source code, there must be a well-publicized means of obtaining the source code for no more than a reasonable reproduction

cost — preferably, downloading via the Internet without charge. The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor or translator are not allowed.

Derived Works — The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software.

Integrity of The Author’s Source Code — The license may restrict sourcecode from being distributed in modified form only if the license allows the distribution of “patch files” with the source code for the purpose of modifying the program at build time. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software.

No Discrimination Against Persons or Groups — The license must not discriminate against any person or group of persons.

No Discrimination Against Fields of Endeavor — The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.

Distribution of License — The rights attached to the program must apply to all to whom the program is redistributed without the need for execution of an additional license by those parties.

License Must Not Be Specific to a Product — The rights attached to the program must not depend on the program’s being part of a particular software distribution. If the program is extracted from that distribution and used or distributed within the terms of the program’s license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the original software distribution.

License Must Not Contaminate Other Software — The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open-source software.

Understanding Closed Source

In Closed Source software, such as Microsoft products, the creators are the only ones who can access and modify the software source code. Of course, this also means that they are the only ones who are authorized to refine, add to, and fix bugs in the software. This is the most restrictive of the software licensing methods.

Selecting Closed Source as the licensing method often draws the wrath of GNU GPL and Open Source supporters. The Open Source and GNU GPL supporters see Closed Source as a restriction that should be lifted to allow anyone to fix, improve, or change the software for the benefit of the software and its community of users. Companies that select Closed Source as the licensing method for the software that they release are often trying to protect “intellectual property,” and therefore see little benefit to opening the software to others. This is a major philosophical difference between Closed Source and Open Source software licenses.

Understanding Artistic License

Artistic License takes a different philosophical approach. It is different from Open Source or GNU GPL because Artistic License is a more restrictive license. Artistic License requires that any modifications to a software package remain in some control of the Copyright Holder. This defeats the reason for Open Source and GNU GPL because if the Copyright Holder does not like the direction (even if it improves the software) the Copyright Holder can stop the changes. Perl is a good example of Artistic License and of the issues that this license can cause.

Is Freeware really free?

Freeware is software that the creator or copyright holder gives away for no charge. This may seem to indicate that the software is not protected by a license. This impression, however, is not accurate because Freeware, even if it is free of charge, is often covered by one of the many licensing methods. Sometimes companies or

14 Part I Linux Basics

individuals will release software as Freeware but control the software under a Closed Source license. This may seem strange, but consider the freeware as a service to introduce users to a company or individual’s software. The company or individual may use the same core programming to create all of the software that they offer, so they may not want to release the code under an Open Source license. Thus, Freeware has no charge, but it isn’t always free.

Is Shareware never free?

Shareware is software that a creator has decided to give away with a string attached. The attached string is that if you want to continue using the software, you must send a payment to the creator. Some creators use the honor system, but most shareware is designed to turn itself off after a certain amount of time. Considering this situation, you may wonder if shareware has to be Closed Source. The answer is no, because it can be licensed under any of the licensing methods; however, it does seem to make more sense to make shareware Closed Source in order to limit the distribution.

A comparison and contrast of licensing methods

Naturally, you should make comparisons when determining which licensing method to select. Keep the following points in mind when choosing a licensing method:

The GNU GPL is restricted to the exact terms of the published GNU GPL and can’t be changed. This is more restrictive than some software authors desire.

The Open Source Licensing method has the GNU GPL as a subset, but it also allows software authors the capability to write their own license, as long as that license follows the Open Source Initiative standards.

Closed Source Licensing is used for any software in which the copyright holder doesn’t want to share the source code of a software package in any way. This is the usual method of licensing by commercial companies and prevents others from using the code to customize the software for redistribution.

This doesn’t mean that Closed Source software is never customized and redistributed. Recently, two of the most popular computer games have had their cores (or engines) licensed to other companies for customization and redistribution as several new games. This is an excellent way for one company to make more money off of a software program while the purchasing company saves development cost.

Artistic Licenses are generally used by software authors who want to give others limited access to the code of a software program. In fact, this is often the case when software authors want to prevent software from being altered too dramatically from the original code.