Creator of Rambo here. Don’t use libraries if you’re writing your own port. Libraries are for working around external programs that cannot be changed.
Your minimal program is a good start, just need to read (block on) standard input on another thread so your MS Project job can run.
If you don’t care about JVM startup time, just run your port with System.cmd on demand. Otherwise if your Java process is long-lived, you’ll need to consider the communication protocol between your Java and Erlang processes.
