Third partyComputer Telephony Integration (CTI) software for Windows is available to integrate Asterisk with desktop productivity applications such as Microsoft Outlook and ACT! through the use of a TAPI driver.
This enables users of TAPI compatible software to dial phone numbers from their desktop computer. Users can select a contact in their software address book, click a dial button, and the call is initiated by the phone system. The users phone rings and the two parties are connected.
Integrating telephony functionality into a desktop contact manager also allows for detailed call logging by the user. Details such as dialed number & call duration can be combined with user entered call notes to create a powerful personal call log. 
The TAPI driver also supports screen-pop applications that display caller-id information on the user’s desktop when an incoming call is received. This functionality can also be used to automatically retrieve caller records from TAPI enabled database applications. When a customer calls, the caller’s records can be automatically pulled up on the user’s screen.
