My classmate Will decided it would be a good idea to use Cobol for our Algorithms class(CMPT 435L). While Ill-advised I couldn't let him struggle without a great environment to struggle in. He pointed out to me zCobol for z390 has Object Oriented support, however, the process to install this environment is tedious and quite confusing.
The docker image can be built from the dockerfile using the make command in the makefile build_image once built it can be run either as standalone or as a development environment by running using the make commands. For a development environment run the make target: run_image_dev which will volume mount the src directory to the container for running your Cobol source code. The Docker image uses the source code found on the z390 site
to run the Portable Mainframe COBOL Compiler use the dos command in the container along with an argument for the file to be used.