does not have GUI, command line dialing, speakerphone, multiple calling cards, audio notification, dials from any document, dials without modem, can use Skype (VoIP), redials on busy, accepts dialing requests from other apps, auto disconnect
CallShop is Windows based VoIP billing application that provides a Solution for Callshops and Cyber Cafes with 4 to 32 booths graphical interface to manage calls. It allows CallShop owner to choose his VoIP provider. Supports most common VPNs
Billion PBX - new generation phone system working in IP-networks using SIP protocol. Billion PBX provides not only voice calls but also a whole range of additional features like call forwarding, voicemail, callback and many others.
Express Talk is software that works like a telephone to let you make calls on your Pocket PC. With Express Talk you can call anyone on the internet who has installed Express Talk (or any other SIP voip softphone). Calls are free.
Pamela Standard allows you to record Skype calls for free. In addition Pamela can play audio files during a call, take notes during or after a call, transfer a call to a contact or group and many more cool features. Pamela looks and works like Skype!