Javascript web application con php

Core WP alone would not do this. You could build a custom WP page that loads jQuery and jCrop. The page could also handle the uploading and emailing aspects as well. This is accomplished by developing a custom page template that contains all the necessary code or loads it by reference.

Truth be told, WP offers little towards this effort other than maybe offering a consistent header and footer that ties in with the rest of your site. You could instead build a stand alone PHP page that does the same thing, but does not make use of any WP resources, including WP header and footer. WP does a better job at email than the PHP’s mail() function, but if the PHP function works for you, you won’t gain much by using WP’s wp_mail() instead.

Thanks for reply. I am sorry if something is still not so clear to me. In particular

You could build a custom WP page that loads jQuery and jCrop

. How can I build this custom WP page? Have I to write code directly? How can I integrate the code in the WP theme I am using? Nonetheless if I build the entire page in php (with jQeuery included), how can I still include this page in the theme I am using? I hope you understand my doubts.
Moreover I didn’t understand your observation on header and footer. Can you give me more details if it could be useful?
Thank you very much indeed.