HTML Form Builder

https://simfatic.com/

http://fancyjs.com/

How JavaScript works: the rendering engine and tips to optimize its performance

https://blog.sessionstack.com/how-javascript-works-the-rendering-engine-and-tips-to-optimize-its-performance-7b95553baeda

JavaScript post request like a form submit

 

Comparing the standard HTML form POST for user authentication vs Javascript/AJAX