Systems

Engine subsystems that make up the Godot runtime, organized by the directory the bulk of their code lives in. The pages here cover the cross-cutting subsystems that ship as part of the engine binary (everything in core/, scene/, servers/, plus the editor). Optional, swappable, or per-platform subsystems are covered under Modules, Drivers, and Platforms.

System	Lives in	One-line summary
Core foundations	core/	Object, Variant, ClassDB, math, IO, OS abstraction, GDExtension
Scene tree and nodes	scene/	SceneTree, Node, Viewport, Window, all built-in node types
Servers and the multi-threaded wrapper	servers/	The "server" pattern, MT wrapping, RID lifecycle
Rendering server	servers/rendering/	RD-based + GL-based renderers, lights, materials, post-process
Physics servers	servers/physics_2d, servers/physics_3d	2D/3D physics APIs over Godot Physics or Jolt
Audio server	servers/audio/	Mixer graph, buses, effects, AudioStream playback
Navigation servers	servers/navigation_2d, servers/navigation_3d	Recast-based navmeshes, agents, regions
Display server	servers/display_server.cpp + platform/<os>/display_server_<os>.cpp	Window, input, clipboard, IME
Text server	servers/text/	Shaping, breaking, BiDi, font fallback
XR server	servers/xr/	XR origin, cameras, trackers; OpenXR/WebXR backends
Editor architecture	editor/	Project manager, EditorNode, plugins, importers, exporters