There is also Onivim although it is not 1.0 yet. Development is financed through selling licenses but it is open source and you can build it yourself. Development has stalled when the main dev got a job some months but there are apparently still people willing to develop it.
Oni2 is not vim. It does not act like vim. It uses neither Vimscript nor Lua, but instead Javascript (VSCode-based extensions).
I paid for an Oni2 licence and regret it, because it isn’t what I want, which is a MacVim.app wrapper for neovim.
If you like MacVim.app, there is _absolutely no GUI that is acceptable_ for neovim. I understand why, and I’m not interested in taking on the development myself. But until someone makes a GUI that is as well-integrated with macOS as MacVim.app, I will be using vim and not neovim.
https://www.onivim.io/