I first came across Standard ML in Dan Grossman's Programming Language course on Coursera[1]. After previously trying Haskell and Scala, this is where the benefits of functional programming and static typing really clicked for me. Really wish the language had caught on outside of academia so I had an excuse to use it more. In addition to the implementations mentioned in the blog post, The University of Chicago created Manticore[2] and Tohoku University in Japan created SML#[3]
[1] https://www.coursera.org/learn/programming-languages