Open-Source Software

You can obtain a tremendous variety of software free of charge or for minimal cost. Many people offer to share programs they have written with others by making them available over the Internet, by posting them on electronic bulletin boards or the Usenet, or by offering to send out CDs or DVDs. Such software is called open source (it used to be called freeware or shareware).

The freeware category of open-source software is exactly that-free. You can obtain this type of software simply by downloading it from the Internet. The shareware category of open-source software consists of software programs that you can evaluate, and-if you find them useful-you can pay a small registration fee to continue using them. Sometimes the author of the software retains certain rights to it, such as prohibiting others from using it in a product they sell. Other authors offer software to users with no restrictions. Software of this type is said to be public-domain software. There is an excellent descriptive breakdown of all of the different terms in the open-source arena at http://www.gnu.org/philosophy/categories.html.

Using open-source software is different from using commercial software products. Commercial products are packaged with installation and operating instructions. They are usually provided as binary files designed to work on specific systems. Vendors of commercial software products offer guarantees and support to their customers, answering questions concerning the installation and operation of their products. Usually, they periodically provide customers who have old versions with updated versions of their software, with discounted prices and instructions for migrating to new versions.

Open-source software, on the other hand, comes with no guarantee. You have to download it from its electronic source, or obtain CDs or DVDs that you have to figure out how to install, sometimes with minimal or no instructions. Because open-source software is sometimes offered in source code form rather than in binary executable form, you may have to compile it yourself. It may be necessary for you to modify the source code to fit your configuration (both hardware and software). You may need to do some debugging. Usually minimal or no support is available for open-source software. However, some authors of open-source software will respond to questions and sometimes will fix problems in their software when other people bring these problems to their attention. In addition, open-source software usually ends up being sponsored by user groups that share ideas on things like how to install the package, bugs, and tips.

If you do have the source code for open-source software, you can alter the code to adapt the program to your specific needs or enhance the program. However, this requires expertise in programming and may be difficult unless the original source code is well documented.

A tremendous variety of shareware is available for the UNIX operating system (usually running on most or all major variants) from various Internet archive sites and CD-ROM or DVD vendors. Some of this software rivals comparable commercial software in functionality and in robustness. In this section, we will present some examples of available applications that you can download and run on many versions of the UNIX operating system, with little or no installation effort. This is just a sampling of the myriad of applications you can obtain. You should use this section as a starting point for learning about UNIX open-source software. You also should use the Internet to find additional shareware.

Although many individuals and groups have provided quality applications, perhaps the largest supplier of quality, freely available software under the open-source category is the Free Software Foundation (FSF). In particular, the Linux operating system, a variant of UNIX, has been built around software provided and maintained by the FSF. Moreover, the FSF supports a tremendous range of additional programs, including many applications. Software for the FSF can be used free of charge and can even be sold in its original or an enhanced form by vendors. However, the resulting software must also be freely available to others.