Ripple can create more XRP

XRP coins can't be created, 100 bln is the total supply (though XRP is burned over time, so that supply goes down). In order for XRP to add more supply they would need to get all of the trusted node operators on board (currently includes companies like Microsoft and MIT, I think within the next year or two Ripple validators will all be offline), at which point there will probably be many large banks and financial institutions that would never agree to something like this. They could just keep running their own nodes and not adopt any changes Ripple wanted to make.

Source and David Schwartz explaining (video)

Oh, and there's this and this.