Linux kernel an SCM system which satisfied Torvalds' technical requirements. BitKeeper was made available to Linus and several others free of charge but was not free software, which was a source of controversy. The system did provide some interoperability with free SCM systems such as CVS and Subversion. In April 2005, efforts to reverse-engineer the BitKeeper system by Andrew Tridgell led BitMover, the company which maintained BitKeeper, to stop supporting the Linux development community. In response, Torvalds and others wrote a new source code control system for the purpose, called Git. The new system was written within weeks, and in two months
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