Software license
From FAS Virtual Worlds Almanac
- This page contains text from Wikipedia's article on Software_license.
A software license (or software licence in commonwealth usage) is a contract between a software publisher and a consumer who uses the software (end-user). A software license grants an end-user permission to use one or more copies of software in ways which would otherwise be prohibited by law. Such a license is required if the end-user wishes to make use of a copy of software, but where such a use would constitute infringement of the software publisher's exclusive rights under copyright law. In effect, the software license acts as a promise from the software publisher to not sue the end-user for engaging in activities that would normally be considered exclusive rights belonging to the software publisher.
[edit] Proprietary vs. open source
Software licenses can generally be fit into one of two distinct categories: proprietary licenses and open source licenses. The features that distinguish the two forms of licensing are significant in terms of the effect they have on the end-user's rights.
[edit] Proprietary software licenses
The hallmark of proprietary software licenses is that the software publisher grants a license to use one or more copies of software, but that ownership of those copies remains with the software publisher (hence use of the term "proprietary"). One consequence of this feature of proprietary software licenses is that virtually all rights regarding the software are reserved by the software publisher. Only a very limited set of well-defined rights are conceded to the end-user. As such, it is typical of proprietary software license agreements to include many terms which specifically prohibit certain uses of the software, often including uses which would otherwise be allowed under copyright law.
The most significant effect of this form of licensing is that, if ownership of the software remains with the software publisher, then the end-user must accept the software license. In other words, without acceptance of the license, the end-user may not use the software at all.
One example of such a proprietary software license is the license for Microsoft Windows. As is usually the case with proprietary software licenses, this license contains an extensive list of activities which are restricted, such as: reverse engineering, simultaneous use of the software by multiple users, and publication of benchmarks or performance tests.
[edit] Open source licenses
With open source licenses, in contrast to proprietary software licenses, ownership of a particular copy of the software does not remain with the software publisher. Instead, ownership of the copy is transferred to the end-user. As a result, the end-user is, by default, afforded all rights granted by copyright law to the copy owner. Note that "copy owner" is not the same as "copyright owner". While ownership in a particular copy is transferred, ownership of the copyright remains with the software publisher. Additionally, open source software licenses typically grant to the end-user extra rights, which would otherwise be reserved by the software publisher.
A primary consequence of the open source form of licensing is that acceptance of open source licenses is essentially optional -- the end-user may use the software without accepting the license. However, if the end-user wishes to exercise any of the additional rights granted by an open source license (such as the right to redistribute the software), then the end-user must accept, and be bound by, the software license.
An example of an open source license is the GNU General Public License (GPL). This license is aimed at giving the end-user significant permission, such as permission to redistribute, reverse engineer, or otherwise modify the software. These permissions are not entirely free of obligations for the end-user, however. The end-user must comply with certain terms if the end-user wishes to exercise these extra permissions granted by the GPL. For instance, any modifications made and redistributed by the end-user must include the source code for those modifications.
