Advanced Textual Confirmation protects your site from the form spam
bbantispam.com/atc
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
An universal antispam for forums, blogs, contact forms, and others. It is a smart textual CAPTCHA, which challenges site visitors only once, and then disappears. To install, no database required, no graphical libraries required, just insert one line into