Alternativer til MTcaptcha for alle platforme med open source-licens

• Alle platforme
  Alle platforme Windows Mac Linux Android iPhone Windows Phone iPad Android Tablet Web Self-Hosted Software as a Service (SaaS) PHP Wordpress Joomla .NET Framework ASP.NET Drupal Drupal Commerce ASP.NET MVC JSP MyAdmin JSP/MySQL Administrador Web
• Open Source-licens
  Enhver licens Gratis licens Open Source-licens Kommerciel licens