SignalR is described as 'ASP.NET SignalR is a new library for ASP.NET developers that makes it incredibly simple to add real-time web functionality to your applications. What is "real-time web" functionality? It's the ability to have your server-side code push content to the connected' and is an app in the development category. There are six alternatives to SignalR for a variety of platforms, including Mac, Windows, Linux, Web-based and Self-Hosted apps. The best SignalR alternative is Socket.io, which is both free and Open Source. Other great apps like SignalR are SockJS, Entity Signal, Higgs.IO and Butterfly Server .NET.