I've watched the lecture series before, it focuses a decent amount on cache oblivious data structures and doing realllllllly cool integer tricks to get things fitting into compact bit maps.
I think it's more likely to be in something much more baremetal, given the topic. My university (UNSW) teaches a similar course with C.
No, it's more likely going to be in LaTeX, given the Erik Demaine's highly theoretical inclinations.
He talks about projects at the beginning of the second session, and implementation (of something that hasn't yet been implemented) is one of the possibilities.