Wbty Forms is a Joomla! component and module bundle for building simple forms.
The components administration interface allows you to create a new form, add different fields to that form as well as easily order them, and set a thank you message and email notice recipient. You can also view responses on the admin side.
The form is rendered either as its own page or in a module position. The form is rendered using Joomla's built in JForm class and JFormField items.
The Captcha field uses the built in Captcha plugin system as part of Joomla. This saves us a bunch of work but requires set up in Joomla. Be sure to enable the "Recaptcha" plugin as well as set it as the default captcha in the Global Configuration section of Joomla.