ROS-1 still has quite a lot of functionality written in and accessible from lisp (c++ and python are the major languages nowadays). irobot was founded by alums

ROS-1 still has quite a lot of functionality written in and accessible from lisp (c++ and python are the major languages nowadays). irobot was founded by alums of the MIT AGI lab, which used lisp extensively. I suspect that's why lisp is in there at all! It's very likely python/cpp nowadays though.