CAPTCHA

CAPTCHAs can be used by MediaWiki wikis to prevent spam. Several implementations currently exist in extensions. Extension:ConfirmEdit is the base framework upon which other CAPTCHA extensions are generally built.

Feature idea
Write a version of reCAPTCHA that uses document images that have been processed by MediaWiki's ProofreadPage extension for Wikisource. In other words, a CAPTCHA that feeds data to ProofreadPage to augment its OCR processing. You might build on existing code. It is worth noting that "reCAPTCHA hold no specific patents for the technology behind their text CAPTCHA algorithms (At least none they discuss on their website or are able to be found on the US Patents & Trademark Office site)", according to one blogger.

Filed as bug 32695.