A quick and dirty demonstration of Window in Rx

Program.cs

using System;
using System.Reactive.Linq;

namespace SlidingWindow
{
    class Program
    {
        static void Main(string[] args)
        {
            var random = new Random();

            Observable.Generate(0, i => true, i => i, i => random.Next(100), i => TimeSpan.FromMilliseconds(random.Next(150)))
                .Where(x => x > 50)
                .Window(TimeSpan.FromSeconds(1))
                .Subscribe(next => next.Count()
                                       .Where(x => x > 5)
                                       .Subscribe(c => Console.WriteLine("Got {0} events at {1}", c, Environment.TickCount)));

            Console.ReadKey();
        }
    }
}