title: How do browsers handle caching of XAP packages?
body: <p>As you know all, you can build a silverlight XAP package and reference it using object tag on your HTML page or asp.net page.</p>
  
  <p>When the browser downloads the XAP package from the server the first time the page is referenced by the user, if the user refreshes the same page, <strong>does it re-download the same XAP package or it uses the cached version?</strong></p>
  
  <p>If the user navigates to another page that uses the same XAP package and the XAP package was already downloaded because of the previous page the user was on, <strong>does the browser used a cached version or go to the server and downloads it again?</strong></p>
  
  <p><em>If the browser uses cached versions all the time</em>, how does it know when to use cached version and when to use new version of XAP package since it may have been rebuild with new changes?  Does it have something to do with the Version number of the package?</p>