Stephen Wolfram is the founder & CEO of Wolfram Research, creator of Mathematica, Wolfram|Alpha & Wolfram Language, author of A New Kind of Science and other books, and the originator of Wolfram Physics Project.
Very fun, feels more like playing a game than reading a book.
Edit: Just finished the book and all of its exercises, and I think it was more exciting starting this book than finishing it. In the first half of the chapters, there are some fancy features like graphics, Geo plotting, or making audio that got me interested. Toward the end, though, while the language has an elegant, concise way of handling functional programming concepts like anonymous functions, it feels a bit non-standard. The book also began bogging me down a bit when going through pattern matching and I noticed the exercises started waning quite a bit. Still a good introduction to the language though, I just think you probably don't need to read all of it if your goal is to say use it as a CAS and graphing calculator. It's probably good enough to just watch a few video tutorials and use it for your own purposes. For most purposes though, I think vibecoding with Cursors AI for example beats out doing it in Mathematica lol. Still a fun read overall!