Wordpress - Does Wordpress have a "Form API"?

No, but it should ;)

There are several custom field class's (backend).

  • wpAlchemy :
  • Meta Box Script:
  • My-Meta-Box:
  • meta-box-class:
  • Meta Boxes Class:

For front-end forms, you probably best off with a plugin in Eugene Manuilov's link.

There is no Form API. Try to use plugin for it. Find it here:

Another custom field library:

Custom Metaboxes and Fields for WordPress

A lot of the 'free' form plugins in the repo are very limited in functionality, but there are options: