The code I have contributed to Rosetta code can be found on GitHub. The Erlang modules that I have modified, and the ones I use as is, are also there. All modules should have the same name as the task, except for the Rosetta Code tasks. I have removed the Rosetta Code part from the code since all modules are about Rosetta Code.
If you are curious about which modules that I have written (vs the ones I only use/modify), look for a task/0 function in the module. I am the only person that have one of those.