As illustrated above, the open source license is becoming more and more dominant, especially as long as the software is provided in digital format. The aim of this article was to observe whether and how the licensing regime of open source software has challenged the protection afforded software by intellectual property rights. Overall, the result is that the distinct production and distribution model of open source licenses, although different, can be compatible with the legal framework of protection of intellectual property rights and serve different purposes. However, a number of remaining uncertainties regarding open source licensing leave room for improvements such as the possibility of making some adjustments to the license terms. The analysis began in chapter two by examining the definition of software and the conditions and circumstances under which it is protected by two intellectual property rights, namely copyright and patent. In the third chapter, the questionable legal nature of the software was examined and the possibilities of exploiting the rights to the software – under license – were explained. Furthermore, in chapter four, the definition of open source was introduced and the main open source licenses currently in use were presented. The resulting conclusion is that open source licensing regimes are no longer limited to idealistic or academic programmers, but have led to the creation of different licenses that provide different possibilities and are consequently more or less compatible with copyright protection. In the fifth chapter, the most important legal disputes from a contractual point of view relating to open source software licenses were examined. This analysis estimated that uncertainty about the contractual nature of… half the paper… world. Reasonable necessity would require new versions of at least the most commonly used open source licenses, which will address the unclear and controversial situations discussed in this article. For example, situations such as definitions of derivative works in the context of software, or laws regarding contracting when software is distributed free of charge, or software patent policies for industry standards, should be spelled out by courts and legislatures . At a general level, the analysis of the relationship between open source licenses and intellectual property rights should be continued to the extent that the system designed for their legal protection and use is still evolving. Perhaps ideas such as regulating open source and reformulating intellectual property laws should be the subject of further discussion on this topic.