Technically it might be an "open-source Google Cast" alternative but it's definitely not an "Open-source Chromecast" alternative. If it was, I would be able to open any app that supports Google Cast and control a device running this software like I can control a Chromecast. But it doesn't support that, and that's what most people are expecting/wanting. It might be a great project but it's not able to provide the tight integration that makes Google Cast so good.
And this title is misleading.