This article summarized 10 Skype Alternatives.
SightSpeed – Mac and Windows app offering unlimited free PC – PC VoIP calls, unlimited free PC – PC video calls. Reduced rates for PC – landline / cell phone calls. Also features video blogging capabilities.
Google Talk – A soft VoIP application for Windows that offers VoIP and instant messaging. Mac users can talk with Google Talk users using Jabber-enabled clients such as Adium and iChat. Linux users can use Gaim.
Gizmo Project – SIP based P2P client in the same ilk as Skype with integrated call recording. At the time of writing, Skype currently requires extra software to record calls.
iChat – Mac OS X application that offers PC – PC calls between iChat and AIM users.
VoIP Buster – Windows app offering free PC – PC calls and 120 days of free calls to landlines.
Jajah – Web-based VoIP interface where you enter your phone number and the number of who you want to dial. Jajah calls the caller and the person you are calling. You both answer, the calls begins and you can talk. Does not require any new software or hardware.
Amicima – Publishers of a soft VoIP application called amiciPhone that offers a combination of user presence, file transfers, photo sharing and instant messaging.
ComBOTS – German app that offers free VoIP calls, photo sharing and drag-and-drop file sharing for files up to 200MB.
OpenWengo – Open Source app based on the SIP protocol for free VoIP calls between 2 PCs with SIP-compliant software. You can hook into any other VoIP provider that uses SIP. Also offers SMS, video chat and instant messaging.
Vbuzzer – Soft VoIP Windows app offer free calls between Vbuzzer users and reduced call rates to landlines. Also offers instant messaging.