Cactus is a software-based private branch exchange (PBX) for Voice over IP telephones.
It runs on any Windows PC with a network adapter and also implements a VoIP-ISDN gateway if an optional ISDN card is plugged into the PC. Cactus is SIP compliant and avoids external IP traffic for internal telephone conversation. For external calls, all SIP-based providers like SipGate can be used.
The new version of Skype for Windows has improved video, sounds, and more view it
Windows Live Messenger has evolved into a full-featured IM application. view it
Take a tour of Windows Live Messenger view it
Google Voice lets you have just one phone number for everything view it
Hate paying expensive fees to send text messages? Here are a few ways to do it for free. view it
Apple and Steve Jobs announce what we can expect to see in the new iPhone OS 4.0 view it