Nvidia's recent stuff is also really cool, but more aimed at raytracing using their new CLAS extensions, rather than raster like Nanite. The main difference is that Nvidia is using SAH splits to partition the mesh, since spatial distribution of triangles is really important for ray tracing unlike raster.

AMD should also be coming out with something like this soon, maybe when RDNA4 launches. Just yesterday they released their DGF SDK, based on the paper they published a bit ago for basically the same thing as Nvidia (except Nvidia does the compression in hardware with an opaque format, rather than leaving it up to devs to implement an open format via an SDK).