Open source software

Open source software is software that is licensed in such a way that the source code (which is the language that computer programs are written in) is freely accessible. The antonym of this is proprietary, closed source software. The term usually describes software that is also free of charge, but this is not a must.

The Open Source Definition

The open source definition was written primarily by Bruce Perens. The definition is broken down into ten key rights:

• Right No. 1: Free Redistribution
  • By free, it is not meant free as in price, but free as in freedom. Open source software must be freely distributed, but the author may choose to charge for this re-distribution. So free software can actually cost money, but free price is often a side effect of open source.

• Right No. 2: Source Code
  • The author of an open source application must provide means of redistributing the full source code.

• Right No. 3: Derived Works
  • Users must be allowed to edit the source code to either improve the software or create a derived work, and should be permitted to distribute the result of their work.

• Right No. 4: Integrity of The Author's Source Code
  • Changes to source code must be clearly distinguished from the work of the original author. For instance, the Songbird multimedia player was derived from the Firefox web browser, but does not reflect the work of its authors, Mozilla. This provision protects the authors from gaining a negative reputation from the problems of changes that others have made to their work.

• Right No. 5: No Discrimination Against Persons or Groups
  • The author of an open source application may not stop any particular person or group from using their software. A commonly used example is that the author may not stop either a pro-life or pro-choice organization from using the software.

• Right No. 6: No Discrimination Against Fields of Endeavor
  • The software must allow use in both a business and a school.

• Right No. 7: Distribution of License
  • The license must be able to be legally distributed along with the software itself. For example, the Linux kernel is published under the GNU General Public License (GPL), which is the most popular, along with the BSD license. If an end-user changes the source code of the Linux kernel, he should be, and is, permitted to use the same license for his derived work.

• Right No. 8: License Must Not be Specific to a Product
  • The license may not limit the use of the software to any certain usage environment. For example, the Slab menu was developed by Novell, but as open source software, it must be permitted to run on other systems, such as Debian and Fedora Core.

• Right No. 9: License Must Not Contaminate Other Software
  • The license must allow the software to be distributed with non-free software. For example, on Mac OS X the Darwin project serves as the operating system and kernel, however the Aqua graphical user interface that gives OS X its "look" is non-free, proprietary Apple software.

• Right No. 10: License Must Be Technology-Neutral
  • The license must allow the software to be distributed by any means, such as compact disk, FTP, flash disks, etc. In particular, the download of the source code must not be limited to any particular interface, such as a Graphical User Interface; it must be accessible from a text-only terminal.

An Open Source project can be tested and used by thousands of users, for example the Apache HTTP Server is the most wiedly used World Wide Web server on the internet.

History

The origins of the open source movement trace back to the free software movement. The term open source and its definition were started by a group of free software advocates who recognized their belief that free and proprietary software could coexist. Unlike the concept of free software, open source was not derived for moral purposes, but rather from the business standpoint. One of the large reasons it began was that the word "free" is not very attractive to businesses who may otherwise use their quality applications. Eric S. Raymond has presented an economy model of open source in his classic essays, The Cathedal and the Bazaar and The Magic Cauldron. Dr. Richard Stallman, the father of free software, to this day differentiates his work from open source because he believes that the morals of community and sharing are more important than the software.

Examples

Perhaps the most notable piece of open source software is the Linux kernel, originally created by Linus Torvalds. This program serves as the core of one of the most popular open source systems. Other open source operating systems include FreeBSD, the GNU system, and ReactOS.

Open source software is not limited to the free Unix platforms, however; many applications have not only been ported to, but written for proprietary systems, such as Microsoft Windows and Mac OS X. Examples of this include the Pidgin instant message client (formerly known as Gaim), the Firefox web browser, and the 7-zip archive manager.

Well Known Organizations

Several professional organizations support the Open Source community, in a moral sense as well as in Legal matters (e.g. enforcing the licensing of Open Source software). Here is a short list:

• Free Software Foundation
• Apache Software Foundation
• RedHat

External Links

• Open Source homepage
• The Apache Software Foundation homepage
• The Free Software Foundation homepage
• RedHat Inc., a Commercial, for-profit company that uses Open Source software extensively
• Eric S. Raymond: The Cathedral and the Bazaar
• Eric S. Raymond: The Magic Cauldron