I don't know because this isn't my area of expertise, but when I use my Firefox browser to load the page with the developer console open, it throws two XML pars

I don't know because this isn't my area of expertise, but when I use my Firefox browser to load the page with the developer console open, it throws two XML parsing errors. So I figure it's one of three things going on here. One, modern browser makers just don't bother testing Acid3 anymore, and bugs have crept into the browser. Two, modern browsers knowingly break Acid3 because they prefer to implement performance enhancements that are not strictly compliant with standards. Three, updated standards have added syntax or rules that invalidate some of the strange stuff that is packed into Acid3.