Many developers are already using the features of HTML 5 and CSS 3 on their sites, but they may worry that older browsers that don’t support those features are going to be left out. Modernizr provides those developers with a way to ensure that no browsers will be left out.
There is no shortage of workarounds for older browsers, including a short JavaScript snippet which helps IE style HTML 5 elements that it can’t understand, as well as a way to make older browsers figure out CSS 3 rules.
Modernizr takes away the strain of working through multiple workarounds. The Modernizr team has taken all of these workarounds and tools and has put them together in one library to help developers make sure that websites and apps that use these new technologies will still work in archaic browsers.
