Create forms of any kind and magnitude with MTFormJS, then add your complex validation, theme in your own style and fashion, and let it go! You may export or import all the data if you need to.
MTFormJS Features: Template-based form components Advanced Validation and Rules Definition Theme-Based Forms Full AJAX (XHR) Support Advanced Event System for Integration of New Modules and Capabilities Multilingual, Integrated, Template-Based Message System
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The beta version yet has not been released.