So... XeLaTeX? Which has been around for over 15 years now? Modern unicode support out of the box? check. Compiles to PDF instead of DVI because obviously? Chec

So... XeLaTeX? Which has been around for over 15 years now? Modern unicode support out of the box? check. Compiles to PDF instead of DVI because obviously? Check. Normal system font support? very check. More than 256 registers? "what the fuck is a register and why would you ever need to care, it's not 1980 anymore." Equal disclaimer: low-key maintainer of ucharclasses.