FSF highlights two projects that can replace Skype
GNU Free Call wants to help people easily connect with each other without relying on any one centralized network. To do that, they’re creating a peer-to-peer calling network, along with client software for traditional desktop computers and mobile devices. The project recently released stable call server software, GNU SIP Witch 1.0, and now the team is beginning to focus its efforts on building the client software.
WebRTC is coordinating an effort to let people call each other and hold videoconferences just by visiting a Web site.