Those slides are my introduction to Fortress. Sounds nice, sorry to hear it's discontinued. I'm struck by how very similar to Julia it is (which is officially inspired by Fortress), for example the focus on performance and maths, zero-cost abstractions, type specialisation, very similar syntax, ASCII<->Unicode equivalence, encouragement of unicode identifiers and operators, and some (small) amount of eliding '*' for multiplication. (You can write "2(a + 1)a^2" but not "(a+1)(a+2)" because the latter is a function call. Whitespace between multiplicands not allowed.)
It seems it would be easy to write a package to display Julia code as HTML or Latex, although I didn't find one. There's already a library to print expressions as Latex, and of course in a Jupyter notebook results are displayed in HTML.