I remember reading about Ada when I was young in 90s. I programmed in Pascal at that time, but was intrigued by Ada’s syntax. I had no book for it sadly and internet was out of reach for me too. Modern Ada looks a bit different too, they definitely added new features into the language. I quite like the syntax.

I never heard about Spark/Ada before. I wonder if anyone uses Spark for real world tasks, and if yes, what for?

Mostly in high integrity computing deployments, those scenarios where people die when software bugs happen.

https://en.m.wikipedia.org/wiki/High-integrity_software

A well known user is NVidia, and car industry security standards.

https://www.adacore.com/press/ada-and-spark-enter-the-automo...