Jenkins offers several different Input fields to enter values.

Textbox

Auto-completion

Start typing a US state for autocomplete results to appear.

Textboxes can feature auto-completion items by Stapler finds this method via the naming convention.

There is a similar control to the autocomplete functionality of "textbox" called combobox:

Dynamic combobox

Like many other fields combo-boxes can be updated dynamically based on other field values:

Number fields

Password fields

Textarea with syntax highlighting

You will want to use f:textarea to pass more CodeMirror configuration if you are doing more than displaying a groovy text editor. There is support for many languages like groovy, xml, yaml, css, javascript, shell, python, perl and many more.
Use the attribute codemirror-config to specify additional key/value pairs in the JSON format (except the start and end bracket) to be passed as CodeMirror option object.

Shell

HTML

To edit html and have a preview you need the OWASP Markup Formatter plugin. Below snippet ensures that when the plugin is not installed that the preview will just print plain text.