As is usually the case with any information technology, the issues related to intellectual property are quite important for open source software. Among the four mechanisms that international legislation provide for protecting intellectual propriety, only three (copyright, patents and trademarks) could be suitable for software. The fourth one, trade secret, is obviously not adequate for open source software, since it requires obscurity (by not having access to source code, in the case of software) or restraint on modifications or resell and redistribution of derived works. None of these requirements are possible with open source software.
In this section we will briefly discuss some of the implications of copyright and patent law when applied to open source software, and the benefits and disadvantages that the open source movement can get from both cases. Trademarks are usually dealt with in similar ways as any other business does, and therefore will not be discussed in detail here. However, they are the basis of many open source business, which deal with the branding of services.
In subsection 3.2, we already discussed several issues relating to open source licences. It was implicit in that discussion that software is covered by copyright law. Unfortunately, in many countries (notably in the United States), copyright is no longer the only way to protect software. Nowadays, patent law is becoming more and more a way of protecting software techniques in some parts of the world.