Have you used the RX.NET library in your projects?

Yes, I have used the RX.NET library in projects for reactive programming and asynchronous data stream processing.

RX.NET allows convenient handling of event sequences using LINQ-like operators for transformation, filtering, and combining streams.

An example of using RX.NET to process a sequence of numbers:

using System;
using System.Reactive.Linq;

class Program
{
    static void Main()
    {
        var numbers = Observable.Range(1, 5);

        numbers
            .Where(n => n % 2 == 0)
            .Select(n => n * 10)
            .Subscribe(
                n => Console.WriteLine($"Received: {n}"),
                ex => Console.WriteLine($"Error: {ex.Message}"),
                () => Console.WriteLine("Sequence completed")
            );
    }
}

This example creates a stream of numbers from 1 to 5, filters even numbers, multiplies them by 10, and outputs the result.