Feng Office - Feng Office is a commercial Open Source web based solution aimed to enhance collaboration and productivity

Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.

LibreOffice - 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.

Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.

Redmine - Flexible project management web application

Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.