title: Tool/API to extract keyword(s) in a sentence in .net
body: <p>I am looking for a tool/api in .net, which can roughly extract the key words in a sentence. For example, if i have a article with title  "PIX: World's thinnest 15-inch laptop, Dell XPS 15z", i want to extract keyword(s), e.g. DELL, XPS 15z, laptop etc. so that i can search those keywords in other articles and present the user with similar articles. </p>
  
  <p>Any suggestions are appreciated.</p>