Alternativas ao Helpninja para Software as a Service (SaaS) com licença gratuita

• Software as a Service (SaaS)
  Todas as plataformas Windows Mac Linux Chrome OS Android iPhone Blackberry iPad Android Tablet Web Self-Hosted Software as a Service (SaaS) PHP Chrome Gmail MySQL Community Edition MariaDB Google Apps Laravel
• Licença gratuita
  Qualquer licença Licença gratuita Licença Open Source Licença comercial