Simple test script - Output with various browsers.
Note the one in the top right corner.
From the known issues:
XML Parsing Errors (affects XHTML and SVG)
No notifications are currently displayed for XML parsing errors encountered while parsing XHTML or SVG. Note that even without notifications, parsing correctly stops and only content occurring before the error is rendered on the page.
Just to point out what (should be) the obvious... :)
As a programmer, the informative display in Opera is really very nice. As a programmer, you want the browser to loudly reject badly formed XML.
Unless you are a programmer, all but the IE display are completely useless. The web is not primarily for programmers. In fact, programmers are an insignificant percentage. To the bulk of the world an XML mis-parse shouts a bunch of completely useless gibberish. This makes no sense.
This could be an (obscure) Monty Python script. Looking at this, what ran though my head...
“Your request was handled at our state-of-the-art service, where thousands machines running the latest, most advanced software available pulled your information from one of the world’s largest databases to assemble your response. Dozens of incredibly faster routers then bounced your response across the Internet at blazing speed. Once at your desktop an amazing electronic brain, capable executing billions of instructions per second, considered how best to present the response.”
Brain: “Ah. I see your response is missing a wizamabidjet. Sorry! You cannot see it!”
User: “What?!?”
“The response is not proper! You cannot see it!”
User: “But all the information I asked for is there! Can’t I see a little of it?”
“Nope! It wouldn’t be proper!”
Clearly I am not sufficiently British to make this funny ... but still - what makes sense to a programmer can be completely absurd to almost the entire Internet audience.