Red Hat is an open source company and I think it really shows in two important ways.
The first way that Red Hat is an open source software company is probably the one you'd expect: everything is open source! All of Red Hat's products are open source. When Red Hat acquires companies, one of the first things they do is work on open sourcing the software. I now get to help with that process.
When Red Hat develops software, they do so in open source. Red Hat, like many open software organizations, distinguishes between upstream and downstream. Upstream is the community project and downstream is the product delivered to customers. Both are open source but a huge effort is made to make sure all new code is in the upstream.