Highcharts is no panacea, but at we just hit performance and capability issues really quickly with all the free stuff out there.
My main complaint is that their pricing is a little odd. Charging per developer doesn't work well for us when we sometimes have 5 devs working on the data vis and other times there are none.
Never seen their licensing before and yeah, that's a messy license for sure.
The way they put it, it sounds like you can just pay for one seat as long as no developers work simultaneously with the highcharts API/source code, so you could have just a note somewhere who currently "owns" the API/source code license in your team, as the cheapest license seems to be 150 USD/seat which is way higher than I would expect from a JS library.
> How do I count Developer seats?
> A developer shall mean any person who will be simultaneously working with the API and/or source code of our software in any capacity.
Would be nice to see more companies offer licensing like this on the lower-end.
"Does what it says on the tin" + "Pay us some amount of money roughly corresponding to your usage" = "Make it easy for a user to pay you money for your product"