GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
hCaptcha - Do you use a captcha to keep out bots? hCaptcha is a drop-in replacement for reCAPTCHA that earns website owners money and helps companies get their data labeled.
MkDocs - Project documentation with Markdown.
MTcaptcha - Enterprise Captcha solutions
Docusaurus - Easy to maintain open source documentation websites
GeeTest CAPTCHA - GeeTest protects your websites, mobile Apps and APIs from bot threats.