FormWow is a Ruby On Rails plugin that simplifies and DRYs up complex forms.
What Does FormWow Provide?
Fully decorated form fields
All of the standard form builder methods are wrapped in a form row with a label, inline form errors, optional hints, required symbols, etc.
Inline form errors
Rather then a large block of error messages appearing in your page's flash message, why not have the errors appear inline with your form field?!
Clean & simple markup
The default form row decorator generates XHTML 1.1 Strict markup. Its very simple and concise.
Use a custom form row decorator
If you don't like the default generated markup for a form row, or have the need to decorate multiple forms, differently you can provide your own decorators (simple to do).
FormWow comes with a sample CSS file to get you started.