VoIP softphone

Express Talk is a VoIP softphone that can be used to call other Express Talk users, or any other SIP voip softphone. The program uses the SIP protocol and is compatible with most major VoIP SIP service providers. Features include support for up to 6 lines, CallerID, data compression, noise reduction, integrated phone book with quick dial and more. Express Talk can be configured to work behind NATs and Firewalls. You will need an account with an SIP provider is order to call other SIP users - the accounts are normally available for free and links are provided.

Freeware