Standalone parsers are exactly what they sound like; separate packages that only parse XML.
More often than not, you will find little need for a standalone parser.
But as long as that constraint was met, I attempted to write each in the most efficient manner for the given language and parser. I'm the maintainer of one of the parsers measured here, the Perl module XML:: Parser. But I'm providing here everything I used to come up with my numbers.
So you're welcome to download what I've got and try it out for yourself.
On the other hand, any attempt to actually parse the document is immediately greeted with an error! (In the next section, you'll learn how to define parameter entries so that we can use XHTML in the elements we are defining as part of the slide presentation.) It is important to recognize that the only reason an exception is thrown when the file fails validation is as a result of the error-handling code you entered in the early stages of this tutorial.