Orleans vs Protoactor: What are the differences?

Developers describe Orleans as "An approach to building distributed applications in .NET". Orleans is a framework that provides a straightforward approach to building distributed high-scale computing applications, without the need to learn and apply complex concurrency or other scaling patterns. It was created by Microsoft Research and designed for use in the cloud. On the other hand, Protoactor is detailed as "Next generation Actor Model framework". It is a Next generation Actor Model framework. It introduces "Actor Standard Protocol", a predefined contract of base primitives which can be consumed by different language implementations. This is a game changer in the field of actor systems, you are now free to pick and choose languages for your different actor based microservices in a way never seen before.

Orleans and Protoactor can be categorized as "Concurrency Frameworks" tools.

Orleans is an open source tool with 6.67K GitHub stars and 1.54K GitHub forks. Here's a link to Orleans's open source repository on GitHub.