open System
open System.Net
open System.IO
open System.Xml

let feed = "http://msmvps.com/blogs/MainFeed.aspx"

let downloadUrl(url:string) =
  let req = HttpWebRequest.Create(url)
  let rsp = req.GetResponse()
  let rst = rsp.GetResponseStream()
  let reader = new StreamReader(rst)
  let str = reader.ReadToEnd()
  str

let xml = downloadUrl(feed)
let doc = new XmlDocument()
doc.LoadXml(xml)

let items =
  [ for nd in doc.SelectNodes("rss/channel/item") do 
      let title = nd.SelectSingleNode("title").InnerText
      let descr = nd.SelectSingleNode("description").InnerText
      yield (title, descr) ]

let keyword = "windows"

items
  |> List.filter (fun (title, descr) ->
      title.IndexOf(keyword, StringComparison.OrdinalIgnoreCase) > 0
      || descr.IndexOf(keyword, StringComparison.OrdinalIgnoreCase) > 0)
  |> List.map fst