Not to detract from the Show HN entry, but I made this back in 2012 to play with 3Delight's API and implicit surfaces: https://vimeo.com/manage/videos/56307994

The one posted to HN is better in several ways, but I was mainly interested in learning about 3Delight.

I'm really curious what bigger hashlife patterns would look like (metacell, etc.) but the visualization gets tricky with that many objects.