Eclipse Origins - This is a free software used to create online multiplayer games for people that don't know how...
Roll20 - Roll20 is a suite of easy-to-use digital tools that expand pen-and-paper gameplay.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
PlanarAlly - PlanarAlly is a web tool that adds virtual battlemaps with various extras to your D&D toolbox.
PlayCanvas - PlayCanvas is an open-source game engine built on WebGL and WebVR.
Astral Tabletop - Create, host, and manage your tabletop role-playing games — online or in person