I think VB would probably do the trick. Read the page into an array just using the HTTP functions, parse the array looking for the data you want, check for differences between those results and the results from the previous parse, then if there are changes open the popup and play the sound. Sleep for a while (the refresh time) and repeat the operation. Does it need to display the page as well? Is the client application a standalone executable or does it need to be a component of some larger system?