The upstream vendor is using open source (mostly GPL) software in their business model. They take software that other people write (Gnome.org, X.org, KDE.org, OpenOffice.org to name a few). They repackage the source files into RPM format for redistribution. Because they chose an open source model to obtain the software they distribute, they must provide their source code to others. That is how the GPL works. The upstream vendor provides much added value by creating the Source RPMS and distributing them. They also fix problems in software and provide feedback to the software developers ... this is what makes open source software work.

The CentOS Project takes the publically available source packages (SRPMS) provided by the upstream vendor and creates binary (installable) packages for use by anyone who wants to use it.

Some packages contain Trademark information and the upstream vendor has specifically created a guide to redistribute software built from their publically available sources. You can read about it here. We support the upstream vendors Trademark rights and strive to be in full compliance with those guide lines.

The CentOS project is not interested in taking credit for work done by others, so where possible we will leave all vendor file names as they are. If we must make any changes to a package (due to trademark restrictions, to setup a configuration file, etc.), it will have a .centosx in the filename (the x is the CentOS version ... 3 for CentOS-3.x, 4 for CentOS-4.x, etc.)

As do most of the other rebuild projects, we change the kernel SRPM and do not label it .centosx. This is because the kernel needs to be exactly the same name to allow 3rd party modules to function.

I would like to thank the upstream vendor for making the SRPMS available in the manner that they do. There are several other enterprise vendors who do not make their source as readily available. Thier product is excellent (or we would not rebuild it as CentOS), as is their support. If you need the support services that they provide, we highly recommend their enterprise product

I would also like to make sure there is no confusion concerning the CentOS Project and the upstream vendor. The CentOS Project is not supported by or affiliated with the upstream vendor in any way. The upstream vendor does not recommend or support any of our offerings in any way.