SyndicationFeed feed = new SyndicationFeed("Feed Title", "Feed Description", new Uri("http://Feed/Alternate/Link"), "FeedID", DateTime.Now);
// Add a custom attribute.
XmlQualifiedName xqName = new XmlQualifiedName("CustomAttribute");
feed.AttributeExtensions.Add(xqName, "Value");

SyndicationPerson sp = new SyndicationPerson("[email protected]", "Jesper Aaberg", "http://Jesper/Aaberg");
feed.Authors.Add(sp);

SyndicationCategory category = new SyndicationCategory("FeedCategory", "CategoryScheme", "CategoryLabel");
feed.Categories.Add(category);

feed.Contributors.Add(new SyndicationPerson("[email protected]", "Lene Aaling", "http://lene/aaling"));
feed.Copyright = new TextSyndicationContent("Copyright 2007");
feed.Description = new TextSyndicationContent("This is a sample feed");

// Add a custom element.
XmlDocument doc = new XmlDocument();
XmlElement feedElement = doc.CreateElement("CustomElement");
feedElement.InnerText = "Some text";
feed.ElementExtensions.Add(feedElement);

feed.Generator = "Sample Code";
feed.Id = "FeedID";
feed.ImageUrl = new Uri("http://server/image.jpg");

TextSyndicationContent textContent = new TextSyndicationContent("Some text content");
SyndicationItem item = new SyndicationItem("Item Title", textContent, new Uri("http://server/items"), "ItemID", DateTime.Now);

List<SyndicationItem> items = new List<SyndicationItem>();
items.Add(item);
feed.Items = items;

feed.Language = "en-us";
feed.LastUpdatedTime = DateTime.Now;

SyndicationLink link = new SyndicationLink(new Uri("http://server/link"), "alternate", "Link Title", "text/html", 1000);
feed.Links.Add(link);

XmlWriter atomWriter = XmlWriter.Create("atom.xml");
Atom10FeedFormatter atomFormatter = new Atom10FeedFormatter(feed);
atomFormatter.WriteTo(atomWriter);
atomWriter.Close();

XmlWriter rssWriter = XmlWriter.Create("rss.xml");
Rss20FeedFormatter rssFormatter = new Rss20FeedFormatter(feed);
rssFormatter.WriteTo(rssWriter);
rssWriter.Close();