Example that uses the TPL Dataflow library to process XML records and output a formatted string.

ProcessPeople.cs

using System;
using System.Globalization;
using System.Threading.Tasks.Dataflow;
using System.Xml.Linq;

internal class Program
{
    private static void Main()
    {
        var inputBlock = new BufferBlock<string>();
        var transformInputBlock = new TransformBlock<string, XDocument>(s => XDocument.Parse(s));
        var processBlock = new TransformBlock<XDocument, Tuple<string, int>>(
            x =>
                {
                    var person = x.Element("person");
                    return Tuple.Create((string)person.Element("name"), (int)person.Element("age"));
                });
        var transformOutputBlock =
            new TransformBlock<Tuple<string, int>, string>(
                t => string.Format(CultureInfo.CurrentCulture, "{0} is {1} years old", t.Item1, t.Item2));
        var outputBlock = new ActionBlock<string>(m => Console.Out.WriteLine(m));

        using (inputBlock.LinkTo(transformInputBlock))
        using (transformInputBlock.LinkTo(processBlock))
        using (processBlock.LinkTo(transformOutputBlock))
        using (transformOutputBlock.LinkTo(outputBlock))
        {
            inputBlock.Completion.ContinueWith(t => transformInputBlock.Complete());
            transformInputBlock.Completion.ContinueWith(t => processBlock.Complete());
            processBlock.Completion.ContinueWith(t => transformOutputBlock.Complete());
            transformOutputBlock.Completion.ContinueWith(t => outputBlock.Complete());

            var records = new[]
                {
                    "<person><name>Michael Collins</name><age>38</age></person>",
                    "<person><name>George Washington</name><age>281</age></person>",
                    "<person><name>Abraham Lincoln</name><age>204</age></person>"
                };
            foreach (var record in records)
            {
                inputBlock.Post(record);
            }

            inputBlock.Complete();
            outputBlock.Completion.Wait();
        }
    }
}