With an increase in OSS awareness, a variety of technology platforms and software categories have come up.

Operating Systems
Many alternatives are available for server operating systems, ranging from proprietary systems like Sun Microsystem’s Solaris and other UNIX variants, to the following prevalent OSS solutions:

• Linux – Released under the GNU General Public License (GPL), it was initially designed to provide low-cost alternative to the UNIX operating system. There are numerous distributions of Linux such as Debian, RedHat, and SuSE. While the penetration of Linux is highest with servers, there is increasing attention to Linux on the desktop.
• FreeBSD – This is an operating system used primarily for server computers, often in data centres. Released under the Berkeley Software Distribution (BSD) license, it is derived from BSD UNIX, a version of UNIX developed at UC – Berkeley.

Server Application Software
This is used to share information and other computing resources on a computer network with many users. E-mail, database, web servers and software to share files and printers are included in this category.

• Apache – It runs on Linux, Sun Solaris, UNIX and Windows 2000, and is used to manage and display web pages.
• MySQL – This is a relational database started in 1995 by MySQL AB, based in Sweden. The product is available under the GNU General Public License (GPL) and a commercial license.
• PostgreSQL – This is a project relational database started in 1986 at UC-Berkeley, released under the Berkeley Software Distribution (BSD) license. It runs on many different operating systems.
• Sendmail - Released under the Berkeley Software Distribution (BSD) license, its development started in 1981, to enable the routing of e-mail between networks.
• Samba – It provides file and printer sharing capabilities, and runs on most UNIX systems, Linux, Sun Solaris and BSD variants.

Desktop Application Software
Consists of a vast array of product categories including personal productivity, games, accounting, graphics and web browsers. While Microsoft’s Office, Internet Explorer and Outlook dominate the desktop, OSS solutions are the following:

• OpenOffice.org – This is an office applications suite, available for Microsoft Windows, Linux, Sun Solaris and Apple Mac OS X systems.
• Evolution – In one application it integrates e-mail, calendar, meeting scheduling, contact management, and task lists.
• Mozilla – This is a web browser available for Windows, Apple Macintosh, Sun Solaris and Linux platforms.

Development Tools
This includes software for creating and developing websites and applications including programming languages such as Perl, PHP and Python. There is also an array of content management solutions available.

Most prevalent Open Source licenses
While open source is associated with Linux and GNU GPL licensing agreement, the open source initiative has certified over 40 different open source licensing agreements. The most prevalent licenses under use are:

GNU General Public Licensing (GPL)
This most widely used license for open source software, was written by Richard Stallman in 1989, for the purpose of distributing programmes released as part of the GNU project. It is considered to be the ‘purest’ by requiring that all source code is free and available, and that changes must be shared with the community of developers.

BSD (Berkeley Software Distribution) License
This is adopted from Berkeley Unix, requiring copyright notification, and permits the source to be used in any manner, as long as notification is provided. The FreeBSD operating system and PostgreSQL databases use this license, and Apple Computer’s OS X is a derivative work based on BSD licensed technology.

Mozilla Public License (MPL)
It defines terms and provides code that can remain propriety under very specific terms, and dual licensing when necessary under the provisions of GPL. This is likely to be a more flexible model for open source organisations. Mozilla, Firebird and Thunderbird Web browsers are available under this license.

Creative Commons License (CCL)
Creative Commons is a non-profit corporation that has created a set of licenses, which others can use to license their creative works. All Creative Commons licenses say that creative works licensed under them may be copied and distributed by others. In addition, one can select additional terms and conditions that apply to others’ use for creative works.

Each of these licenses state that the source code is open and users are free to use, copy, duplicate, distribute and modify them. <

Reference: Open Source Software, by Paul Dravis, infoDev