I took a PL/Compilers course based on COOL with Wes Weimer at UVA. We built an interpreter and compiler for COOL using its manual (i.e. a document with a verbal/maths spec for the language) and virtually no skeleton code. It was the hardest class in the department and I consider it to be the most valuable class I took as an undergrad. Before that class I didn't really understand what happened when I 'hit go' on my programs. Weimer is at UMich now but still publishes course materials online: https://web.eecs.umich.edu/~weimerw/
