> Polars will remain MIT-licensed and the company will sponsor and accelerate the open-source development of Polars.
I bet that they will change to a custom business source available license sooner or later.
From the about page: [0]
> We successfully closed a seed round of approximately 4M$, which was lead by Bain Capital Ventures.
Waiting for the day that a seperate closed-source version of polars gets built / forked privately and improvements do not make it back into the source.