This is amazing. Is the author of the OS also the author of the language? The language looks pretty high-level; why was it chosen for the OS implementation? What architecture does the kernel have (monolythic, micro, etc.)?

Yes having custom language allows us to fine-tune it for the needs of the OS. It was intended for games and game engines, but later I extended it to the osdev too. The design of Hexa implies balance of high-level feel and moderate safety by default without compromise on performance. You may always go lower or higher level when needed. Kernel is a game-engine inspired experimental design. For simplicity, you may assume its a monolith (with some internal sandboxing, but that's not yet fully implemented). I will cover Tofita design in the future as it evolves.