MicrosoftMvcJQueryValidation.js is used by ASP.NET MVC 2 for client side validation.
MicrosoftMvcJQueryValidation.js
Having problems with this file just not working properly and wonder
As of Dec 17, 2009 the latest version of MicrosoftMvcJQueryValidation.js is available in the futures download project.
Be careful to include MicrosoftMvcJQueryValidation.js and NOT the similarly named MicrosoftMvcValidation.js.
MicrosoftMvcValidation.js