After having a look into different CMS systems our homepage kernel went from a self developed Java/J2EE web application to a simple wordpress installation. We added a new style based on the current twenty-twelve theme. While implementing we learnt about modernizr (www.modernizr.com) to programmatically check for browser support of specific CSS styles / HTML features. This homepage applies it to determine the browser support of the border-image css style.
Another nice online tool is browsershots.org. It allows to check how your homepage renders on different browsers. Beware you have a limited amount of shots per days there, so i would recommend starting with the browsers of interest first.