A screenshot from Yum Extender in Fedora 8

The Yellowdog Updater, Modified (YUM) is an open-source command-line package-management utility for RPM-compatible Linux operating systems and has been released under the GNU General Public License. It was developed by Seth Vidal and a group of volunteer programmers. Though yum has a command-line interface, several other tools provide graphical user interfaces to yum functionality.

As of mid 2007 Seth Vidal works for Red Hat, and a number of other Red Hat programmers are involved in the development of yum.

As a full rewrite of its predecessor tool, Yellowdog Updater (YUP), yum evolved primarily in order to update and manage Red Hat Linux systems used at the Duke University department of Physics. Since then, it has been adopted by Red Hat Enterprise Linux, Fedora, CentOS, and many other RPM-based Linux distributions, including Yellow Dog Linux itself, where it has replaced the original YUP utility.

System administrators can automate software updates using yum-updatesd, the yum-updateonboot package, the yum-cron package, or PackageKit.

Yum's XML repository, built with input from many other developers, quickly became the standard for RPM-based repositories. Besides the distributions that use Yum directly, SUSE Linux 10.1 adds support for Yum repositories in YaST, and the openSUSE Build Service repositories use the YUM XML repository format.

However Yum has moved to a dual approach in its repositories, where .sqlite meta-data database files are directly downloaded. This is a significant optimization.

Automatic metadata syncing

Yum automatically synchronizes the remote meta data to the local client, with other tools opting to synchronize only when requested by the user. Having automatic synchronization means that yum cannot fail due to the user failing to run a command at the correct interval.

Yum repositories

A separate tool, createrepo, sets up yum repositories, generating the necessary XML metadata (and the sqlite meta data if given the -d option).

The mrepo tool (formerly known as Yam) can help in the creation and maintenance of repositories.

Plug-in/module system

The 2.x versions of yum feature an additional interface for programming extensions in Python that allows the behavior of yum to be altered.

A commonly installed package yum-utils, contains commands which use the yum API, and many plugins.

Graphical front-ends

• PackageKit ? the default Yum graphical front-end for Fedora as of Fedora 9
• Pirut ? the default Yum graphical front-end for Fedora from Fedora Core 5 to Fedora 8
• Pup ? Package Updater Fedora GUI
• Yum Extender ? an alternative Fedora GUI for Yum
• KYum ? GUI for Yum on KDE

External links

• Yum website
• yum command tutorial ? Explains how to update and install packages under Redhat Enterprise Linux ver 5.0
• Managing packages with yum ? Describes how to use yum to manage packages

References

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