(This project is no longer under development.)
Monkland is an online multiplayer mod for Rain World originally developed by https://github.com/ZandrXandr (Original here: https://github.com/ZandrXandr/Monkland) and later forked by https://github.com/Garrakx (Fork here: https://github.com/Garrakx/Monkland). For a multiplayer mod that is currently in developement and has multiple very skilled developers working on it see: https://github.com/henpemaz/Rain-Meadow.
Check out the Rain Meadow Project for a better multiplayer mod