1. Google's encompassing suite of cloud-based business apps.

  2. Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online

  3. From desktop to web for Macs and PCs, Office delivers the tools to get work done. View product information or sign in to Office 365.

  4. Microsoft Office is an office suite of desktop applications, servers, and services for the Microsoft Windows and OS X operating systems.

  5. Free office suite, open source, and compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files. Updated regularly – download for free. Originally based on OpenOffice.org.

  6. Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more.

  7. Microsoft Word is a commercial word document processor for Windows.

  8. Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft.

  9. Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite.

  10. Web-based IMAP email client

  11. hMailServer is a free e-mail server for Microsoft Windows.

  12. Apache OpenOffice is an open source, office document productivity suite.