There is also MRAM [0] which ships from a company called Everspin [1][2] and is produced by Globalfoundries. Unlike Intels/Microns solution it seems to be as fast as normal RAM, but at much smaller densities.

[0] https://en.wikipedia.org/wiki/MRAM

[1] https://www.everspin.com/ddr3-dram-compatible-mram-spin-torq...

[2] https://www.everspin.com/ddr4-st-mram-products