Concrete has been around since 2003, this major version update that has been a year in the works and is major version release 5. While our content management system has always been "open source" to our clients, who paid for it; this is the first fully "free beer" open source release we've done. We're giving away our secret sauce and we're thinking how to protect the years and millions in development that have gone into it.
We've come to recognize it's the brand. We will trademark our name as Concrete5™ – and make money by being the official host, trainer, documenter, and support provider. Conversely we may look at any of those roles and tap a better suited partner as an "Official Concrete5 Solution" in return for some license or revenue model.
The Ruby on Rails guy looks to have similar ideas around his brand and license model, which is also MIT.