Absolutely. Horizon PPM is a platform not just a service. It has been designed with an internal API (Application Programming Interface) that allows secure integration and data sharing with existing systems.
The Horizon PPM Alexa voice service is an example of this integration using the API. The Horizon PPM Alexa skilll can be downloaded from the Amazon App Store and set-up to interact with their project protfolios through simple commands issued to an Amazon Echo device.
Please raise a ticket if you would like to discuss any of the technical details or require custom integrations.