Warp is a feature-rich framework for multiplayer games, written in GameMaker and NodeJS (previously GM-Online-Framework)

Collection of nice stuff for Godot

A curated list of Multiplayer Game Network Programming Resources

Realtime application framework (Node.JS server)

⚔ Multiplayer Framework for Node.js

Collaborative Drawing Prototype. Using Colyseus + HTML5 Canvas

Colyseus SDK for godot

Reliable & unreliable messages over UDP. Robust message fragmentation & reassembly. P2P networking / NAT traversal. Encryption.

An ecosystem of tools for Godot Engine and Valve's Steam. For the Windows, Linux, and Mac platforms.