TouchEngine is a standalone executable that loads a .tox file and uses Custom Parameters on it's top-level, as well as In and Out nodes at the top-level as ways to send in and get data out of the process. Other processes communicate with the TouchEngine process using the TouchEngine API.
The TouchEngine API allows other software packages to load TouchDesigner .tox files, process them, and pass data back and forth.
The API, documentation and example project for Windows are available here:
The Engine COMP works with any license including Non-Commercial licenses.
Other implementations/applications using TouchEngine require an Educational, Commercial, or Pro TouchDesigner/TouchPlayer license on the end-user's machine run. Additionally TouchDesigner/TouchPlayer must be installed on the system to use TouchEngine.
There is no licensing fee or royalty required to make use of TouchEngine API within your software package. It can be included in any software package for free, and the feature becomes enabled by the end-user installing a paid TouchDesigner/TouchPlayer license on the machine.
Engine COMP - The Engine COMP is a native component in TouchDesigner that loads .tox component files into a project yet runs them on a separate TouchEngine process.
Unreal Engine Plugin - The TouchEngine-UE4 Plugin allows Unreal Engine users and developers to load TouchDesigner .tox files, process them, and pass data back and forth from within Unreal Engine.