It is an extensible and highly configurable jquery plugin which allows validation of the HTML5's forms while the user is typing It is extensible because it allows the programmer to define new restrictions beyond those already defined by HTML5 It is highly configurable because not only does it allow changes to the validation rules defined by HTML5, but also the addition of new ones. Moreover, although assuming, by default, behaviors and ways to flag the errors in a very intuitive manner, it also provides the developer with complete freedom to redefine or even suppress them.