Looks very similar to the unobtrusive validation used in ASP.NET MVC (which in turn relies on jQuery validation) although this does seem to add richer configura

Looks very similar to the unobtrusive validation used in ASP.NET MVC (which in turn relies on jQuery validation) although this does seem to add richer configuration of behaviour (such as when the validation is triggered etc.) from here: http://bradwilson.typepad.com/blog/2010/10/mvc3-unobtrusive-validation.html http://bradwilson.typepad.com/blog/2010/10/mvc3-unobtrusive-... <input class="text-box single-line" data-val="true" data-val-length="The field LastName must be a string with a maximum length of 60." data-val-length-max="60" data-val-required="The LastName field is required." id="LastName" name="LastName" type="text" value="" /> <span class="field-validation-valid" data-valmsg-for="LastName" data-valmsg-replace="true"></span>