What does Open Source Software mean?
In the late 1980's some computer science academics working on computer operating systems, believed it would be good to give access to the program's source code so that other software engineers could study, improve, debug, and make it more nimble. All of this access was free from requiring any monetary payment by the user. As more and more source code was released on the Internet, in order to avoid misunderstandings about what this new freedom meant, some in the free software movement adopted the term "open source" to emphasize that the freedom being promoted was software freedom by readily giving access to the source code and that it did not mean "freedom" from all obligations, as the code being released was protected under copyright and in some cases patent law.
What does Open Source (OS) Licensing mean?
The promoters of the open source movement decided it would be useful to clarify the underlying principles that would support the exchange between one software developer freely giving access to her source code and the circumstances under which another developer could make use of that code. By consensus, the open source promoters adopted an Open Source Definition which identified the principles which must be incorporated in any qualified OS license. Any computer programmer wishing to release software source code must use a form of OS license that has been approved by the board of directors of the Open Source Initiative. With this stamp of approval for an OS license, others in the open source community are willing to use and work on the released software.
What is the General Public License (GPL)?
There are now numerous Open Source Initiative approved OS licenses, but in the beginning there was just one, the General Public License. The intent of the drafters of the GPL, was to bring more and more software under the OS umbrella. This would be accomplished by the hereditary nature of the GPL. Those who obtain access to OS software under the GPL are required to re-license the software under the exact same terms as the GPL. Important requirements in the GPL are that the user must not charge for the further distribution of the underlying software and must also make the source code, including their additions, available to the downstream users.
The General Public License, which is maintained by the Free Software Foundation, has gone through two modifications so that version 3.0 was released on June 29, 2007. However, because much software was released under the terms of the GPL, due to its hereditary nature, its terms remain profoundly influential.
What is a proprietary software license?
When a software engineer writes code for someone else, it may be that she does not want the user to know the inner workings of the product, thus it will be distributed in object code (machine readable only). Similarly, the business contracting for a software application may want to keep its operation confidential from those outside of the business. Those developing or using the applications would consider such software as proprietary and it would come under a license that would emphasize its confidential nature.
However, when creating proprietary software, the developer must be certain that all of the software in the program is either original to that developer or she has permission to use it which does not limit the subsequent use or distribution of it. If, in the process of writing code, a developer incorporates some OS software into the application, the whole program may be subject to the same licensing requirements under which that OS code was originally released.
