Azure Functions Runtime

This runtime provides a new way for customers to take advantage of the Functions programming model on-premises. Built on the same open-source roots that Azure Functions service is built on, Azure Functions Runtime can be deployed on-premises and provides a near similar development experience as the cloud service.

• Harness unused compute power: It provides a cheap way for customers to perform certain tasks such as harnessing the compute power of on-premises PCs to run batch processes overnight, leveraging devices on the floor to conditionally send data to the cloud, and so on.
• Future-proof your code assets: Customers who want to experience Functions-as-a-Service even before committing to the cloud would also find this runtime very useful. The code assets they build on-premises can easily be translated to the cloud when they eventually move.

Source: Introducing Azure Functions Runtime preview