Richard Stallman Mellon's Mach microkernel in a project called GNU Hurd, which has yet to achieve the maturity level required for full POSIX compliance. In 1991, Linus Torvalds, a Finnish student, used the GNU's development tools to produce the free monolithic Linux kernel. The existing programs from the GNU project were readily ported to run on the resultant platform. Most sources use the name "Linux" to refer to the general-purpose operating system thus formed, while Stallman and the FSF call it "GNU/Linux". This has been a longstanding naming controversy in the free software community. Stallman argues that not using GNU in the
Fedora (operating system) installed using the DNF package manager or GNOME Software. Additionally, extra repositories can be added to the system, so that software not available in Fedora can be installed easily. Software that is not available via official Fedora repositories, either because it doesn't meet Fedora's definition of free software or because its distribution may violate US law, can be installed using third-party repositories. Popular third-party repositories include RPM Fusion free and non-free repositories. Fedora also provides users with an easy-to-use build system for creating their own repositories called Copr. Since the release of Fedora 25, the operating system defaults to the