Question: Is is possible to insert user-editable text as a form component?

I would need some custom text between the "email" and "name" fields. How do I achieve this?

Answer: 
Assuming you are talking about the [Webform](http://drupal.org/project/webform) module, you can create an element with type of "markup". There are a few options for this, including input format. If you have everything configured properly, you can use a WYSIWYG editor on the fields, too.

If you are using the [Form API](http://api.drupal.org/api/drupal/developer!topics!forms_api_reference.html/7), then you can use [`#type = "markup";`](http://api.drupal.org/api/drupal/developer!topics!forms_api_reference.html/7#markup) to put pretty much whatever HTML you want in your custom form.
In Drupal 8, you now have *Markup elements* you can look for by *Category* when adding elements to your webform. This is confusing at first since the *markup* element is no longer called so in the Drupal 8 version.