Alternativas ao sevDesk para Software as a Service (SaaS) com licença de código aberto

• Software as a Service (SaaS)
  Todas as plataformas Windows Mac Linux Android iPhone Windows Phone Apple Watch iPad Android Tablet Kindle Fire Web Self-Hosted Software as a Service (SaaS) PHP BSD Slack npm
• Licença Open Source
  Qualquer licença Licença gratuita Licença Open Source Licença comercial