> Open core is a relatively new model where a business exists to commercialize open source software. That's a bit too broad. Open core is when part of a produc

> Open core is a relatively new model where a business exists to commercialize open source software. That's a bit too broad. Open core is when part of a product, the "core", is FOSS, but official first-party extensions to it are proprietary, e.g., GitLab CE vs. EE, and VirtualBox with its Extension Pack.