Orleans
Orleans is a cross-platform, open-source framework for building distributed, scalable, and high-performance applications using the virtual actor model. It simplifies the development of cloud-native services by abstracting away complexities like concurrency, fault tolerance, and state management, allowing developers to focus on business logic. Originally developed by Microsoft Research, it is now part of the .NET Foundation and supports .NET and .NET Core.
Developers should learn Orleans when building large-scale, stateful distributed systems such as online games, IoT platforms, or real-time analytics services, as it provides built-in scalability and resilience without requiring manual handling of distributed computing challenges. It is particularly useful in scenarios requiring high throughput and low latency, as the actor model enables efficient parallel processing and automatic load balancing across servers.