An anonymous Slashdot reader reports that "This challenge sat around, gathering upvotes but no answer, for four years. Then, it was answered." Citing the work of seven contributors, a massive six-part response says their solution took one and a half years to create, and "began as a quest but ended as an odyssey." The team created their own assembly language, known as QFTASM (Quest for Tetris Assembly) for use within Conway's mathematical universe, and then also designed their own processor architecture, and eventually even a higher-level language that they named COGOL. Their StackExchange response includes a link to all of their code on GitHub, as well as to a page where you can run the code online.
One StackExchange reader hailed the achievement as "the single greatest thing I've ever scrolled through while understanding very little."