Would love to see more open source competitors in this space. I was excited when I saw a Github link, but that's basically hosting just a README and the only one I know of is GeoPix [0], but to be fair I haven't used either LX Studio or GeoPix. LX Studio does look exciting though, I will evaluate it on my next LED mapped project. A few projects I've done in the past have been playing with Enttec ELM [1] which is also not open source (but does not have a vague license like LX Studio and is fairly priced). A really neat feature of that software though is you can map GLSL shaders over your stages.
[0] GeoPix: https://github.com/EnviralDesign/GeoPix
[1] ELM: https://www.enttec.com/product/dmx-lighting-control-software...