I created a new intermediate language, called Bril, for teaching my funky open-source, hands-on compilers course. Because it’s for education, Bril prioritizes simplicity and regularity over more typical compiler priorities like performance and concision. This is an overview of Bril’s design, its quirks, and the ecosystem that has grown up around it since 2019.
R. Kent Dybvig’s compilers course has had approximately 15 “intermediate” representations designed for his course since at least 2004 – a consequence of teaching the course using the nanopass compiler framework for scheme. You could broadly divide these into “representations that are restrictions of scheme,” and “representations that are increasingly-annotated versions of UIL” where UIL is the underlying intermediate representation. As far as I know, UIL was also designed for this course.