GNU/Linux naming controversy lacking. The GNU kernel was called GNU Hurd. The Hurd followed an ambitious design which proved unexpectedly difficult to implement and has only been marginally usable. Independently, in 1991, Linus Torvalds released the first version of the Linux kernel. Early Linux developers ported GNU code, including the GNU C Compiler, to the kernel. The free software community adopted the use of the Linux kernel as the missing kernel for the GNU operating system. This work filled the remaining gaps in providing a completely free operating system. Over the next few years, several suggestions arose for naming operating systems using 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