LibreCaptcha - Framework that allows developers to create their own CAPTCHAs

LibreCaptcha is a framework that allows developers to create their own CAPTCHAs. The framework defines the API for a CAPTCHA generator. It provides an HTTP interface for serving CAPTCHAs, Background workers to pre-compute CAPTCHAs and to store them in a database, Managing secrets for the CAPTCHAs (tokens, expected answers, etc), Safe re-impressions of CAPTCHA images (by creating unique tokens for every impression) and lot more.