Alternatif untuk Bookis untuk Microsoft Exchange Server dengan lesen sumber terbuka

• Microsoft Exchange Server
  Semua platform 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 Sunbird Google Apps Microsoft Exchange Server Apple Calendar
• Lesen Open Source
  Mana-mana lesen Lesen percuma Lesen Open Source Lesen komersil