- O que é: X-Rate-Limit
- O que é: X-Frame-Options
- O que é: X-Content-Type-Options
- O que é: XMPP (eXtensible Messaging and Presence Protocol)
- O que é: XSS (Cross-Site Scripting)
- O que é: XBRL (eXtensible Business Reporting Language)
- O que é: XaaS (Anything as a Service)
- O que é: XHTML (eXtensible HyperText Markup Language)
- O que é: XML (eXtensible Markup Language)
