Kestrel 
Kestrel is used by 0.05% of sites
Official Website
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/servers/kestrelCategory
Web ServersKestrel is an open-source, lightweight, and high-performance message queue and event bus system developed by Microsoft. It is part of the broader Azure Service Fabric framework and is designed for building scalable and distributed applications.
Key features and characteristics of Kestrel include:
Lightweight and Fast: Kestrel is built to be lightweight and optimized for performance. It is written in C# and utilizes asynchronous I/O operations, making it highly efficient and capable of handling a large number of concurrent connections.
Cross-Platform: Kestrel is cross-platform and runs on various operating systems, including Windows, Linux, and macOS. This flexibility allows developers to deploy Kestrel-based applications on different platforms and environments.
Web Server Capabilities: Kestrel can act as a standalone web server, serving HTTP and HTTPS requests. It supports HTTP/1.x and HTTP/2 protocols and provides features like request/response pipelining, connection pooling, and server push.
Integration with ASP.NET Core: Kestrel is the default web server used by ASP.NET Core, Microsoft's cross-platform web application framework. It seamlessly integrates with ASP.NET Core and provides a scalable and high-performance hosting environment for ASP.NET Core applications.
WebSocket Support: Kestrel supports the WebSocket protocol, enabling bidirectional communication between client and server. This is particularly useful for real-time applications, such as chat systems, live updates, and collaborative tools.
Customizable Pipeline: Kestrel allows developers to configure and customize the request processing pipeline. It provides middleware components that can be added or removed to modify the behavior of the server and handle various aspects of the request/response cycle, such as authentication, compression, and caching.
Integration with Azure Service Fabric: Kestrel is designed to work seamlessly with Azure Service Fabric, a distributed systems platform for building microservices-based applications. It can be used as a messaging system and event bus within Service Fabric clusters to facilitate communication between services.
Extensibility and Integration: Kestrel can be extended through middleware components and integration with other libraries and frameworks. It supports various protocols and can be used in conjunction with other messaging systems, such as Azure Service Bus or RabbitMQ, to create more complex and scalable distributed architectures.
Kestrel provides a reliable and efficient solution for building web applications and microservices that require high performance, scalability, and cross-platform support. Its integration with ASP.NET Core and Azure Service Fabric makes it a popular choice among .NET developers for building modern, cloud-native applications.
Key features and characteristics of Kestrel include:
Lightweight and Fast: Kestrel is built to be lightweight and optimized for performance. It is written in C# and utilizes asynchronous I/O operations, making it highly efficient and capable of handling a large number of concurrent connections.
Cross-Platform: Kestrel is cross-platform and runs on various operating systems, including Windows, Linux, and macOS. This flexibility allows developers to deploy Kestrel-based applications on different platforms and environments.
Web Server Capabilities: Kestrel can act as a standalone web server, serving HTTP and HTTPS requests. It supports HTTP/1.x and HTTP/2 protocols and provides features like request/response pipelining, connection pooling, and server push.
Integration with ASP.NET Core: Kestrel is the default web server used by ASP.NET Core, Microsoft's cross-platform web application framework. It seamlessly integrates with ASP.NET Core and provides a scalable and high-performance hosting environment for ASP.NET Core applications.
WebSocket Support: Kestrel supports the WebSocket protocol, enabling bidirectional communication between client and server. This is particularly useful for real-time applications, such as chat systems, live updates, and collaborative tools.
Customizable Pipeline: Kestrel allows developers to configure and customize the request processing pipeline. It provides middleware components that can be added or removed to modify the behavior of the server and handle various aspects of the request/response cycle, such as authentication, compression, and caching.
Integration with Azure Service Fabric: Kestrel is designed to work seamlessly with Azure Service Fabric, a distributed systems platform for building microservices-based applications. It can be used as a messaging system and event bus within Service Fabric clusters to facilitate communication between services.
Extensibility and Integration: Kestrel can be extended through middleware components and integration with other libraries and frameworks. It supports various protocols and can be used in conjunction with other messaging systems, such as Azure Service Bus or RabbitMQ, to create more complex and scalable distributed architectures.
Kestrel provides a reliable and efficient solution for building web applications and microservices that require high performance, scalability, and cross-platform support. Its integration with ASP.NET Core and Azure Service Fabric makes it a popular choice among .NET developers for building modern, cloud-native applications.