Microsoft has made its broadest challenge to date against open-source software, including Windows rival Linux, claiming that such programs violate 235 Microsoft patents and saying it will seek licence fees. The world’s largest software company said that various open-source packages violate patents it holds in areas related to graphical user interface, e-mail programs and other technologies.

Microsoft sent the statement to reporters on Monday via e-mail, detailing a stance that it disclosed in an article that appeared in Fortune Magazine. Linux is the most popular type of open-source operating system, or computer programs that developers can download and modify as long as they share those changes with the public. The packages, which are often available for free, have gained in popularity over the past 7-8 years, taking huge market share away from Microsoft. While dozens of versions of the Linux operating system are available for free download, Red Hat Inc. and Novell Inc. develop and sell versions of Linux used to run servers and mainframe computers in corporate data centers. However, this move of microsoft has once again started the battle between open source and commercial softwares.