Depends on what you mean by Open Data.

There are lots of companies that aggregate ranking/keyword data from Google, package it and sell it as a product to SEO companies. Examples include WordTracker, SEMRush, Moz, etc. It's data you and I can get through Google ourselves, but it's almost impossible to get in aggregate.

It depends on how you package the data. You need to present it in a way that can be actionable and help someone towards a business problem.