Retired
Components
This page described the 1.x game engine. That engine is preserved
(the engine-v1 branch, final release v1.2.1) and no longer developed.
Hearth is now an app for agentic game development: you describe a game, a coding agent builds it in a folder on your disk, and the game runs beside the conversation while it works. None of the 1.x editor machinery this page covered ships anymore.