Salesforce.com CTI Toolkit
The 4.01 version of Salesforce.com CTI Toolkit is available as a free download on our website. Salesforce.com CTI Toolkit is included in System Utilities. This download was scanned by our built-in antivirus and was rated as virus free. The most popular version among Salesforce.com CTI Toolkit users is 4.0. This free software was originally developed by Salesforce.com, inc.
From the developer:
The Force.com Connect CTI Toolkit allows developers to create integrations to telephony systems. It is just a toolkit, and so it can be connected to just about any telephony protocol, including (but not limited to) TAPI, CSTA, and proprietary protocols.
You may want to check out more software, such as Salesforce Reports for Excel, Salesforce for Outlook or Popup Toolkit, which might be similar to Salesforce.com CTI Toolkit.