One of the situations I've seen is roughly: System is up: returns XML or JSON or pretty-format-of-the-week System is down: It returns a HTML IIS error page. I

One of the situations I've seen is roughly: System is up: returns XML or JSON or pretty-format-of-the-week System is down: It returns a HTML IIS error page. In the second case, all you might want is to extract the content of the first <h1> tag out of that error page. That's predictable enough of a task that a Regex might be able to handle it, especially if at that point you've already iven up on a full success and you're just salvaging a prettier error message than "system error".