Some licenses make use of this term. The common definition for the term “contributor” is: a person who contributes to the maintenance of a software program, including debugging, updating, revision or other modifications. As free software development is seldom done by one single person but rather achieved with the help of a networked community, the term contributor refers to this communal effort. Contributor can refer to both the original developer and the authors of any derived program. In the broadest definition, contributor can also refer to authors of a “patch”, which is not considered as a derivative work. Some obligations set by the terms of a certain free software licenses are meant for this kind of contributors. Take the obligation of making source code open as an example, although legally speaking patches are not derivative works of the original program, some licenses requires nonetheless patch authors to open the source code of the patches. The point is that, even though patches are not derivative works, they still aim to perform functional modifications to the original program. In any case, more specific definition of the term depends on the respective licenses, some of which have slight variations on the meaning of the term.