In most case in these companies it's maintained and created at the expense of the company. I would expect that 90-99%% of the code, product development (talk to users, understand needs, etc), even devrel (marketing) (be on every conference to convince people to use it, that codification is good)- it's a lot of money, resources, and effort.
> New startup, cool idea, not much budget to hire engineers
In this case a few folks build it from the ground initially (most likely founders) I think. Please, let's not forget about this.
The important thing here is to discuss why did they do this (I meant relicensing it). Most likely- trying t create a moat from a lot of other VC-funded companies that play in this space? Not sure. It would be great to know their exact concern.