Frequently Asked Questions
What is "open source software"? What is the "GPL"?
Open source software is a term used to describe software where the source code (the fundamental instructions that make the software work) is publicly available to view, modify and use without charge. It is part of a widespread movement in software development that has proved successful at producing significant, robust and secure software. Two of the best-known examples of open source software are the Linux operating system, and the Apache web server, both of which are widely used globally today. Open source software is also known as "free software", and although open source software is usually provided without charge, the meaning of "free" here is as in "freedom", not as in without charge ("free as in freedom, not free as in beer").
Open source software is provided to users on the terms specified in the license that accompanies the software code. While there are now many different open source licenses available, there are two major categories, the "BSD" style license, and the "GPL" style license (eg, the GNU General Public License or "GPL"). In addition to the general concept of publicly viewable software code, both types of licenses are based on requirements that use of the software must be acknowledged in some form, and a disclaimer of any kind of liability for using the software.
The key difference between these licenses is that the GPL (but not the BSD) requires that any additions to the software made by third parties must also be released as open source software under the same terms as the original license (ie, the GPL) if the additions are distributed. This requirement normally helps to encourage a viable, growing community of developers contributing to the growth of the software from a common basis. This community development can also occur with BSD style licenses, although there is no license requirement on developers to "require" them to make their additions available to the community under the same license as the original system if they distribute their additions. The GPL requirement described above is sometimes called "share alike", on the basis that the others who wish to benefit from the initial open source software release are required to share their additions on the same basis as the initial release.
The Open Source Institute is recognised as the leading authority on open source licensing. It has a certification program for open source licenses to ensure that these licenses meet the principles of the Open Source Definition — a fundamental statement of open source principles. The GPL and BSD licenses are "OSI Certified" licenses, and hence when LAMS is released under the GPL in February 2005, it will be released using an OSI Certified license.