WebRTC technologies are an opportunity for achieving a real convergence between WWW, desktop and mobile multimedia real-time communications services, which will contribute to defeating fragmentation and shall provide significant advantages to users and developers all around the world. Following this vision, in this paper we introduce Kurento, a media server technology based on open source software capable of demonstrating how this convergence could take place by combining a SIP/HTTP based signaling plane and a powerful media server infrastructure built on top of the GStreamer software stack. The presented technology is suitable for sending and delivering real-time multimedia through different protocols and formats and capable of providing advanced processing capabilities, which include media mixing, transcoding and filtering. Thanks to this, Kurento could push current WebRTC capabilities beyond plain peer-to-peer communication.