Description of iSoftPhone program at Mac Shareware: An easy to use Internet phone for Mac OS X using VoIP to provide crystal clear voice quality in an attractively sleek interface, quick configuration, integrated with OS X address book and supporting Growl notifications.

Xnet Communications, a maker of market leading Captain FTP, introduces new Telephony Software, specifically designed for the Mac.
This is no half-baked Apple Java-compatible program nor is it a port of any Windows or Linux version. This is a pure Mac implementation for Mac users only. Therefore user experience is set on top of the powerful telephony engine.

iSoftPhone is an easy to use Internet phone for Mac OS X using VoIP to provide crystal clear voice quality in an attractively sleek interface. The quick configuration will allow you to get talking to other Megafon users in seconds. iSoftPhone is integrated with the Mac OS X address book to make calls and manage contacts. Simply dial the number of the person you wish to talk with or select them from contacts to call. Users may also setup conference calls for multiple contacts. Create private telephone networks by using the option to add multiple SIP providers.

iSoftPhone is a free to try software. You can free download and try it for an evaluation period.