Copyleft In Software Applications
There are different types of copyleft licenses. There is the strong copyleft, and there is the weak copyleft. The strength of the copyleft is expressing the extent of restrictions provided for in the work of an author from which the license is derived.
Weak licenses are used in creating software libraries and they allow for other software’s to link up with the library. These licenses are redistributed without any legal restrictions under the library’s copyleft license. Only changes necessary for the weak-copylefted certificates are compiled and linked to the libraries. The most common free software license is the GNU also referred to as the General Public License. The strong copyleft license can also apply itself to any project, and not only documents the literature, music, video or photography, it also applies itself to contents on the open source.
There also exists full and partial copyleft issues. In the full copyleft, all parts of a project can be redistributed and modified under certain agreed terms and conditions. The partial copyrights on the other part, exempts parts of the project from copyleft restrictions and allowing users under the license not to impose any principle of copylefting on the work.
Another name for Copylefting is Viral Licensing. It is defined as any part of a work derived from copylefting must reserve the copyleft permissions when distributed.