Compared to other similar plugins, quickValidation.js is extremely easy to use and supports a plethora of validation methods, along with error notifications.
Only input text fields and textareas can be validated, but as Nik Korablin, the plugin's developer explained, checkboxes and radio buttons don't really need to be validated because they can have default values.
From required fields, to numbers, integers, phone numbers and up to email addresses, quickValidation.js supports many validation rules, and with a little hard-coding, custom rules can be added with ease.
Check out a demo of quickValidation.js here. If anyone is interested, the project's development is now handled via a GitHub account.
Download quickValidation.js from our Scripts section here.