Apart from WebViews, the most common layer types used for integration with other applications are Spout and NDI.
Creating a Spout Layer
Spout is a texture sharing toolkit (https://spout.zeal.co/ ) and enables applications to acts as Spout senders and receivers. The toolkit works locally and both the senders and receivers must be using the same graphics card (GPU).
Press the Add Content button and select New > Spout.
This creates a new layer which acts as a Spout receiver.
The layer properties on the right hand side displays a dropdown list of currently available Spout senders.
The Spout toolkit contains a demo SpoutSender.exe program which creates a sender called Spout DX11 Sender. Run this program and select the demo sender. This will appear as a rotating cube in the workspace as shown below.
Creating an NDI Layer