It comes with TeX Live. You can get it today, or five years ago, for that matter. But the final version, for which there is a plan, has not shipped or been wr

It comes with TeX Live. You can get it today, or five years ago, for that matter. But the final version, for which there is a plan, has not shipped or been written. Writing it is a very ambitious task and takes time, and a little money (through support from, e.g., the TeX Users Group). Things take time.