Open Source Software

Overview Open source  is a set of principles and practices on how to write software, the most important of which is that the source code is openly available. Open source is defined at Webopedia. The open source definition, which was developed by Bruce Perens and Eric Raymond, adds some meaning to the term. It states that one should not only get the source code but have the right to use it. The open source definition is currently maintained by the Open Source Initiative (OSI).  The open source definition is used by the OSI to determine if a software license can be considered open source. For some history of the OSI, click here.  For reliably updated news about open source software click this link to the

Linux Open Source For many people, one of the first things that come to mind when thinking about open source software is the Linux operating system. Linux is a Unix-like computer operating system. The name "Linux" comes from the Linux kernel, started in 1991 by Linus Torvalds. (For a biography of Linus Torvalds click here.) The system's utilities and libraries usually come from the GNU operating system, announced in 1983 by Richard Stallman. The GNU contribution is the basis for the alternative name GNU/Linux. Linux is one of the most prominent examples of free software and open source development. Typically, all underlying source code can be freely modified, used, and redistributed by anyone.

Linux Open Source Download Sites There are many distributions of Linux available currently. A comprehensive database of the numerous distributions can be found rated according to popularity at the Web site. There are descriptions of each distribution as well as links for downloading each distribution. Take a look at The Hungry Penguin for advice on which Linux versions to choose as a beginner or advanced user.  Live distributions (no installation required) and mini versions of Linux are also discussed. This page provides a list of some of the most popular versions of Linux and links to download them.

General Open Source Download Sites There are many Web sites on the Internet that offer open source software for Windows, Macintosh, and Linux platforms. is the world's largest and most popular open source software development Web site. provides free hosting to open source software development projects with a centralized resource for managing projects, issues, communications, and code. Another  very popular location for downloading open source software is the  Open Source Software Directory.  The World Wide Web Consortium (W3C) offers its own open source software, available for download or use at  

Windows Open Source Download Sites Open source software for Windows can be found at the Open Source Windows Web site. Open Source Windows is a simple list of the best free and open source software for Windows. This is not a comprehensive list; instead it showcases the best, most important, and easiest to use. A list of open source software for Windows can be reviewed at the popular Web site.  This list is searchable and can be browsed by tags, license types, and operating system types.

Mac Open Source Download Sites Popular open source software available for Macintosh computers can be downloaded from the Open Source Mac Web site. Open Source Mac is a simple list of the best, most important, and easiest to use open source software. The Free OpenSource Software Mac User Group (FreeSMUG) has a directory of Mac OS X free open source software. The FreeSMUG also offers tutorials, info, news, and help for end-users as well as free and open source Mac software. There is a list of recently available open source downloads for the Mac OS X at the Apple Web site called  Unix & Open Source: Most Recent.

Portable Open Source Software A portable application is a software program that does not require any kind of formal installation and can be stored on a removable storage device such as a CD-ROM, USB flash drive, or flash card, enabling it to be used on multiple computers.  Portable open source software applications are gaining in popularity and are available for all of the major OS platforms. offers many open source software applications that can run from any portable hardware (USB flash drive, iPod, portable hard drive, etc) on Windows.  Read "Portable, Open Source Applications on a USB Flash Drive" by Dr. Steve Yuen for an interesting article and slide show about portable open souce software applications as they pertain to education.  Take a look at the tutorials at for information about how to boot and run different Open Source Linux distributions from a USB Flash drive. A portable desktop can be carried with you wherever you go! Finally, a comprehensive list of portable open source software can be found at the No Thick Manuals Web site. 

Other Links For a discussion of how open source software differs from commercial software, how open source software is developed, as well as other interesting topics, take a look at the article entitled "What is Open Source" by Dan Woods. In the book "Open Sources: Voices from the Open Source Revolution", leaders of Open Source come together in print for the first time to discuss the new vision of the software industry they have created through essays that explain how the movement works, why it succeeds, and where it is going.