Alternativy k Skeduly pro Slack s licencí open source

• Slack
  Všechny platformy Windows Mac Linux Chrome OS Android iPhone Windows Phone iPad Android Tablet Web Self-Hosted Software as a Service (SaaS) PHP jQuery Windows Mobile Slack Microsoft Office Outlook Chrome Google Calendar Drupal Google Apps Microsoft Exchange Server Apple Calendar
• Licence Open Source
  Jakákoli licence Bezplatná licence Licence Open Source Komerční licence