Similar to nodered, a visual-editor for connecting different services and APIs. More focused on service-to-service connections in the cloud (i.e. more Zapier than node-red). Can even make use of AI endpoints.

Allows more advanced workflows between services to be created but carries slightly less focus on maker-related IOT devices. Good introduction and feature overview (between Home Automation, NodeRed and this) by Andreas Spiess.

Lastly, not a true OSI open source license, but contains anti-competitive commercial prohibitions. I am okay with it but YMMV.