The Logger class can be extended to support logging information to virtually any conceivable data repository. Just create and use the backend that best supports your needs. For most uses, the fileLoggerBackend class should be the most appropriate, but there are some definite advantages to using a database.
The Debugger class gives you functionality similar to the Logger class but allows the information to be displayed on the screen and stored in the session for display, even if the original page request contains no output.
In the next chapter, you'll meet SOAP Simple Object Access Protocol and learn how PHP5 is just perfect for writing both clients and servers that take advantage of this protocol.