Note
Prior to using yum, you must import the RPM-GPG-KEY for CentOS-4 like this
rpm --import /usr/share/doc/centos-release-4/RPM-GPG-KEY
The following files are changed from the upstream RPMS.  All changes are trademark and look/feel related unless otherwise noted under the specific RPM.
- anaconda 
Path of the Distribution changed from RedHat to CentOS on the install CDs.
- anaconda-help 
- anaconda-product 
- anaconda-runtime 
- apr and apr-devel 
These packages required a rebuild due to an upgrade gcc.  Nothing is changed, as it is an automatically generated requirement.
- centos-release 
File name changed from redhat-release in the upstream product.
- desktop-backgrounds-basic 
- desktop-backgrounds-extra 
- devhelp and devhelp-devel 
These packages required a rebuild due to an moving from mozilla to seamonkey.  Nothing is changed, as it is an automatically generated requirement.
- dhcp-devel 
- firefox 
In addition to numerous shortcut changes, added the CACert.org certificate as a trusted Certificate Authority.  See CentOS.org for details.
- firstboot 
- fontconfig and fontconfig-devel 
Required rebuilding to fix an issue with i386 and x86_64 man pages so that they can both be installed on x86_64.
- glade2 
Corrected a race condition.  See bug#855 at bugs.centos.org.- gnome-desktop 
- gnome-desktop-devel 
- gnome-session 
- httpd 
- httpd-devel 
- httpd-manual 
- httpd-suexec 
- indexhtml 
- initscripts 
- libtool and libtool-devel 
These packages required a rebuild due to an upgrade gcc.  Nothing is changed, as it is an automatically generated requirement.
- mod_perl 
- mod_perl-devel 
- mod_ssl 
- redhat-artwork 
- redhat-logos 
- redhat-release and rpmdb-redhat 
These packages are replaced by centos-release and rpmdb-CentOS.
- rhgb 
- rhn-applet 
Modified to not use the RHN and to instead use the CentOS Mirror Network.
- seamonkey 
In addition to numerous shortcut changes, added the CACert.org certificate as a trusted Certificate Authority.  See CentOS.org for details.
- seamonkey-chat 
- seamonkey-devel 
- seamonkey-dom-inspector 
- seamonkey-js-debugger 
- seamonkey-mail 
- seamonkey-nspr 
- seamonkey-nspr-devel 
- seamonkey-nss 
- seamonkey-nss-devel 
- squirrelmail 
- thunderbird 
In addition to numerous shortcut changes, added the CACert.org certificate as a trusted Certificate Authority.  See CentOS.org for details.
- up2date 
Modified to not use the RHN and to instead use the CentOS Mirror Network.
- up2date-gnome 
Note:
 The following packages are newer on the CentOS-4.4 ISO than the upstream ISO due to security updates released after the upstream ISO:
- firefox-1.5.0.5-0.el4.1.centos4 
- freetype-2.1.9-4.el4 
- freetype-demos-2.1.9-4.el4 
- freetype-devel-2.1.9-4.el4 
- freetype-utils-2.1.9-4.el4 
- gnupg-1.2.6-6 
- httpd-2.0.52-28.ent.centos4 
- httpd-devel-2.0.52-28.ent.centos4 
- httpd-manual-2.0.52-28.ent.centos4 
- httpd-suexec-2.0.52-28.ent.centos4 
- iproute-2.6.9-3.EL4.3 
- irb-1.8.1-7.EL4.6 
- krb5-devel-1.3.4-33 
- krb5-libs-1.3.4-33 
- krb5-server-1.3.4-33 
- krb5-workstation-1.3.4-33 
- libtiff-3.6.1-12 
- libtiff-devel-3.6.1-12 
- mod_ssl-2.0.52-28.ent.centos4 
- ruby-devel-1.8.1-7.EL4.6 
- ruby-docs-1.8.1-7.EL4.6 
- ruby-libs-1.8.1-7.EL4.6 
- ruby-mode-1.8.1-7.EL4.6 
- ruby-tcltk-1.8.1-7.EL4.6 
- thunderbird-1.5.0.5-0.el4.2.centos4 
- tzdata-2006g-1.EL4 
- wireshark-0.99.2-EL4.1 
- wireshark-gnome-0.99.2-EL4.1 
The kernel version is the same as the upstream ISO for 3rd pary driver compatibility; however, there is a security update to kernel-2.6.9-42.0.2.EL.  We highly recommend updating the kernel as soon as possible after installing CentOS-4.4.
Note:
 The following packages are added to CentOS and are not in the upstream product to allow the use of yum for updates:
- createrepo 
- centos-yumconf 
- sqlite 
- sqlite-devel 
- python-elementtree 
- python-sqlite 
- python-urlgrabber 
- yum 
For more Information, see the 
CentOS-4  Documentation at CentOS.org, or the /NOTES directory on CD-1 of this distribution.  The documentation is provided {and copyrighted} by 
Red Hat®,Inc.  The CentOS Project redistributes these original works (in their unmodified form) as a reference for CentOS-4.  CentOS-4 is built from publicly available, open source SRPMs.
Major changes this upgrade cycle include replacing etherreal with wireshark, replacing mozilla with seamonkey, upgrading firefox and thunderbird from the 1.x series to the 1.5 series, and upgrading OpenOffice.org from the 1.1.2 to the 1.1.5 series. See the U4 notes in the /NOTES directory for more details.