Assuming I wanted to pick up COBOL and land a contract gig, what else do I need to know? A language is syntax but also libraries, patterns, and ecosystem. For instance it's hard to do Rails without knowing Git, Bash, Linux, SQL, Javascript, CSS, RSpec, Capistrano, Devise, MVC, etc. Do COBOL apps typically talk to relational databases, or is everything stored in fixed-width flat files? Do COBOL programmers use git? Am I going to need to keep an AS/400 running in my garage?
There are COBOL repositories on Github[1], it would probably be worth looking at what they do. From that list, here's a micro web framework[2] which while it may not be indicative of what you would expect to do in COBOL if hired to work in it, is interesting.