Yum (software)

The Yellowdog Updater Modified (YUM) is a free and open-source command-line package-management utility for computers running the Linux operating system using the RPM Package Manager. Though YUM has a command-line interface, several other tools provide graphical user interfaces to YUM functionality. YUM allows for automatic updates and package and dependency management on RPM-based distributions. Like the Advanced Package Tool (APT) from Debian, YUM works with software repositories (collections of packages), which can be accessed locally or over a network connection. Under the hood, YUM depends on RPM, which is a packaging standard for digital distribution of software, which automatically uses hashes and digital signatures to verify the authorship and integrity of said software; unlike some app stores, which serve a similar function, neither YUM nor RPM provide built-in support for proprietary restrictions on copying of packages by end-users. YUM is implemented as libraries in the Python programming language, with a small set of programs that provide a command-line interface. GUI-based wrappers such as YUM Extender (yumex) also exist, and has been adopted for Fedora Linux until version 22. A rewrite of YUM named DNF replaced YUM as the default package manager in Fedora 22. This was required due to Fedora's transition from Python 2 to Python 3, which isn't supported by YUM. DNF also improves on YUM in several ways - improved performance, better resolution of dependency conflicts, and easier integration with other software applications. The original package manager, Yellowdog UPdater (YUP) was developed in 1999-2001 by Dan Burcaw, Bryan Stillwell, Stephen Edie, and Troy Bengegerdes at Terra Soft Solutions (under the leadership of then CEO Kai Staats) as a back-end engine for a graphical installer of Yellow Dog Linux. As a full rewrite of YUP, YUM evolved primarily to update and manage Red Hat Linux systems used at the Duke University Department of Physics by Seth Vidal and Michael Stenner.