Spout does for Windows what Syphon does for macOS: applications share textures directly on the graphics card, so a TouchDesigner patch can feed Resolume, or a game engine can feed OBS, without capture hardware or perceptible delay.
The framework is open source and near-universal in Windows visual software, to the point that a tool’s Spout support is assumed rather than advertised.
Together with Syphon and NDI, it completes the routing trinity of modern rigs: Spout within a Windows machine, Syphon within a Mac, NDI across the network between them.
Photism sends Spout from its output window on Windows, in the VST3 and the standalone app. It is a beta: turn it on in the top bar, pick the Photism source in your receiver, and tell us how your card and receiver behave.