Language Details: Standard ML

Standard ML is a general-purpose, modular, functional programming language with compile-time type checking and type inference; and a descendant of the ML programming language used in the Logic for Computable Functions theorem-proving project.

Standard ML article on Wikipedia
Code Jam 2012 Contestants using Standard ML
Qualification Round
Used in 8 solutions by 4 contestants:

Submission Origin

India (1 contestant)
Sweden (1 contestant)
United Kingdom (1 contestant)
United States (1 contestant)