Criticism of Linux rise in prominence of operating system-level virtualization using Linux has raised the profile of attacks against the kernel, and that Linus Torvalds is reticent to add mitigations against kernel-level attacks in official releases. Linux 4.12, released in 2017, enabled KASLR by default, but its effectiveness is debated. Con Kolivas, a former kernel developer, tried to optimize the kernel scheduler for interactive desktop use. He finally dropped the support for his patches due to the lack of appreciation for his development. In the 2007 interview "Why I quit: kernel developer Con Kolivas" he stated: At LinuxCon 2009, Linux creator Linus Torvalds
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