HTML Validators

Hi there,

I have noticed that there are many HTML Markup Validation Services on the web besides the one offered by http://validator.w3.org/.  I tried running my pages through the different validators and got different results with each.  Some would say the page is free of errors and warnings, while others would say it is not.  Why is this so?

Best Regards,
 
Steve Riley
http://www.kepware.com