CentOS的很多软件的安装都需要先添加RPMforge

原文地址：http://wiki.centos.org/Repositories/RPMForge

RPMforge is a collaboration of Dag and other packagers. They provide over 5000 packages for CentOS, including wine, vlc, mplayer, xmms-mp3, and other popular
media tools. It is not part of Red Hat or CentOS but is designed to work with those distributions.

RPMforge for CentOS 5

The default RPMforge repository does not replace any CentOS base packages. In the past it used to, but those packages are now in a separate repository (rpmforge-extras) which is disabled by default.

You can find a complete listing of the RPMforge package packages at http://packages.sw.be/

Download the rpmforge-release package. Choose one of the two links below, selecting to match your host's architecture. If you are unsure of which one to use you can
check your architecture with the command uname -i

i386 http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.i386.rpm

x86_64 http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.x86_64.rpm

The preferred rpmforge-release package to retrieve and to install in order to enable that repository is one of the two listed above.

Install DAG's GPG key

rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt[/code] 
Verify the package you have downloaded
rpm -K rpmforge-release-0.5.2-2.el5.rf.*.rpm



Security
warning: The rpmforge-release package imports GPG keys into your RPM database. As long as you have verified the md5sum of
the key injection package, and trust Dag, et al., then it should be as safe as your trust of them extends.

Install the package
rpm -i rpmforge-release-0.5.2-2.el5.rf.*.rpm


This will add a yum repository config file and import the appropriate GPG keys.

Then try to install something。