Red Hat is
the open source company, cheesy as that sounds. They don't lock anything but support, patent indemnification and ISV certifications behind a paywall. Don't want to pay for RHEL, they provide the SRPM's they used to build all their packages, go grab a rebuild (CentOS, Scientific Linux) and go to town (we use CentOS at work to run mission-critical loads, if we decide we need support later we can always switch). This is universally true of literally every product they have, from Satellite (Foreman+Pulp+Candlepin) to RHEV (oVirt), JBoss products, IdM (FreeIPA), storage (glusterfs+ceph).
Red Hat isn't a company that makes money by taking open source projects as a base and adding proprietary features on top, everything they make is under an open source license and anyone (regardless of whether the paid for it or not) can grab the source packages off their FTP server and build it themselves. Contrast this to Canonical who sells proprietary tools for Ubuntu (Landscape, a big sore spot for me), kept Launchpad proprietary for the longest time, Ubuntu One (though this is now dead).
And then we have the other big name in "Enterprise" Linux, SUSE, and we've got loads of proprietary software their sister companies sell (Novell, NetIQ) from eDirectory to GroupWise, the list here goes on.
Red Hat is an engineering organization dedicated to one thing. Sure, they have a sales channel and a large partner ecosystem, but at the core of their business is making fully open source products that people want to use (and hopefully buy support for).