Faster Than Light

Faster Than Light was a low-latency media streaming protocol developed for use by Microsoft’s Mixer live streaming service. With this protocol users could enjoy very low latency, below 1 second, between streamers and viewers, allowing for unprecedented levels of real-time interactivity. After the closure of Mixer in July 2020, I decided to build my own implementation of the FTL protocol.


Shortly after Mixperiment64 came to life, Microsoft announced that they would be closing the Mixer live streaming service.

Sadly, at the time, Microsoft Mixer was the only big live streaming service capable of true sub-second latency between streamer and viewer via their “Faster Than Light” or FTL protocol. I was bummed, because I had just begun experimenting with live streaming experiences that required low latency in order to keep the viewer engaged with the interactive experience.

Building It

Although the SDK provided for developing applications to stream to Mixer via FTL was open source, the server-side implementation was proprietary.

After poking around the client-side SDK, I documented my findings and proceeded to hack together my own server-side implementation of FTL as a plugin for Janus, a popular WebRTC streaming framework that Mixer also utilized.

Within a couple weeks I had a promising prototype running with latency comparable to what Mixer was providing.

What’s Next

I’m continuing to work with a group of fine folks to integrate this technology with, a new community-driven open-source streaming platform!