Alternativas ao Tasks para Slack com licença de código aberto

• Slack
  Todas as plataformas Windows Mac Linux Chrome OS Android iPhone Windows Phone Apple Watch Android Wear iPad Android Tablet Kindle Fire PlayBook Web Software as a Service (SaaS) Firefox Safari BSD PortableApps.com Slack Chrome GNU Emacs Install Chrome Extensions Google Chrome to Phone
• Licença Open Source
  Qualquer licença Licença gratuita Licença Open Source Licença comercial