If you have ever loved Drupal it is probably at least in part because of the genius of the FAPI. Though sometimes daunting to newcomers, the FAPI enables fast form creating and processing entirely in PHP. Often more importantly, it allows any form in a Drupal site to be altered using hook_form_alter functions.
The concrete5 Form Helper
concrete5 provides a Form Helper that reminds me of Code Igniter and other framework form helpers. It promises to save time in form creation compared to writing the full HTML tags. It also handles the data persistence on POST.
The Form Block that comes with Concrete5 is very simple to use for building forms directly inside a page. So for users that just want to create a contact form or another simple form, they will find they can do this with minimal fuss. This compares in some ways to Drupal Webform module, but with far less learning required to use. It also ships with concrete5, so it is available right away for use.
concrete5 also provides a Form Validation helper that provides basic testing of form input.