Coppeliasim has a free educational version and is very capable for simulation, though it's not as streamlined for robot-agnostic code generation as RoboDK.
RoboDK is a software package for simulating and programming industrial robots. It allows users to create robot programs, generate robot code, and simulate robot movements. The software supports a wide range of robots from various manufacturers and can be used for tasks such as welding, painting, grinding, deburring, and pick and place. robodk full crack 2021