Alternativas ao MeetApp para Google Apps com licença de código aberto

• Google Apps
  Todas as plataformas Windows Mac Linux Chrome OS Android iPhone Windows Phone iPad Android Tablet Web Self-Hosted Software as a Service (SaaS) jQuery Windows Mobile Slack Microsoft Office Outlook Chrome Google Calendar Google Apps Microsoft Exchange Server Apple Calendar
• Licença Open Source
  Qualquer licença Licença gratuita Licença Open Source Licença comercial