What web page were you looking for? If your web browser is broken, you might have got here by following a link to a different web page,
http://www.lemis.com/why\backslashes\are\not\slashes.html . That's not this page, which has the URL
The problem is that some Microsoft-centric web browsers corrupt URLs, changing the backslashes (\) into slashes (/). If your browser is broken in this manner and you follow the link above, you'll just end up back here. You should be able to get to the correct page with the workaround of replacing the \ with its hexadecimal equivalent, %5C: http://www.lemis.com/why%5Cbackslashes%5Care%5Cnot%5Cslashes.html. If this doesn't work for you with your browser, please let me know.
For further details, look at the definition of URIs in RFC 2396.