Free software had become frustrated with the effects of the change in culture of the computer industry and its users. Software development for the GNU operating system began in January 1984, and the Free Software Foundation (FSF) was founded in October 1985. An article outlining the project and its goals was published in March 1985 titled the GNU Manifesto. The manifesto included significant explanation of the GNU philosophy, "Free Software Definition" and "copyleft" ideas. The Linux kernel, started by Linus Torvalds, was released as freely modifiable source code in 1991. The first licence was a proprietary software licence. However, with version 0.12
Operating-system-level virtualization system's resources. They include: The operating system may be able to allow or deny access to such resources based on which program requests them and the user account in the context of which it runs. The operating system may also hide those resources, so that when the computer program enumerates them, they do not appear in the enumeration results. Nevertheless, from a programming point of view, the computer program has interacted with those resources and the operating system has managed an act of interaction. With operating-system-virtualization, or containerization, it is possible to run programs within containers, to which only parts