Web-based Productivity Applications:

This list is not comprehensive, but rather is just a short listing of some of the FREE web-based options that are available as alternatives for traditional desktop office suite applications:  

Word Processing:

• Zoho Writer
• Writely
• Think Free
• gOffice
  

Spreadsheets:

• Google Spreadsheets
• Zoho Sheet
• Think Free
  
• gOffice
• NumSum
  

Presentations:

• Zoho Show
• Goffice
  
• Think Free
  

Calendars & Planners:

• Zoho Planner
  
• 30 Boxes