接触过的有licode、kurento.
licode的缺陷：文档支持有限，licode的app client库只有js的
kurento的优势：文档齐全，Demo俱备，封装API比较齐全。它的主要特性：
- Networked streaming protocols, including HTTP, RTP and WebRTC.
- Group communications (MCUs( Multipoint Conferencing Unit) and SFUs(Selective Forwarding Unit.) functionality) supporting both media mixing and media routing/dispatching.
- Generic support for computational vision and augmented reality filters.
- Media storage supporting writing operations for WebM and MP4 and playing in all formats supported by GStreamer.
- Automatic media transcodification between any of the codecs supported by GStreamer including VP8, H.264, H.263, AMR, OPUS, Speex, G.711, etc.
除了以上特性，kurento对于我们要做的WebRTC MCU服务，有专用的Room API，方便实现此类功能。其丰富的视频处理功能也是选用这个解决方案的重要原因之一。也可以基于kurento做Peer2Peer的信令服务。