Correction, Lean4 [1] is sponsored by Amazon, the lead developer, Leonardo de Moura is at AWS now [2]. He was previously at Microsoft Research [3]. Meeting him is a real ride, I only had the chance to talk with him once.
[2] https://leodemoura.github.io/about.html
[3] https://www.microsoft.com/en-us/research/blog/the-inner-magi...