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.
Kontact - Kontact is the integrated Personal Information Manager of KDE.
Drupe - Next generation contact manager and dialer.
Open Contacts - Open Contacts is an advanced address book program for managing contact info of individuals and...
Simple Contacts - Contact lens prescriptions from home
Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.