First Programmable Memristor Computer

https://en.wikipedia.org/wiki/Memristor#Background

And I'm going to assume GP is basically referring to the first paragraph of the next session regarding definition and criticism:

According to the original 1971 definition, the memristor was the fourth fundamental circuit element, forming a non-linear relationship between electric charge and magnetic flux linkage. In 2011, Chua argued for a broader definition that included all 2-terminal non-volatile memory devices based on resistance switching.[2] Williams argued that MRAM, phase-change memory and ReRAM were memristor technologies.[21] Some researchers argued that biological structures such as blood[22] and skin[23][24] fit the definition. Others argued that the memory device under development by HP Labs and other forms of ReRAM were not memristors, but rather part of a broader class of variable-resistance systems,[25] and that a broader definition of memristor is a scientifically unjustifiable land grab that favored HP's memristor patents.[26]

In the 90s somebody at HP must have mentioned memristors in hearing range of their marketing department and suddenly HP was going to have a product to market in a few years.

Yeah. Never happened. Nobody's done it.

In theory, such a device could allow us to do things like build extremely low power non-volatile memory (a flash replacement, basically). A lot of marketing hype has talked about completely replacing computer RAM with non-volatile memristor-backed memory, but again, neither it nor anything like it has happened. But as it turns out, battery-backed DRAM covers a multitude of sins anyway.

The actual debate over physical possibility is because it's too low-power, to the point that an actual implementation might violate lower theoretical limits on the amount of energy required to change the state of a bit. In other words, it might violate the second law of thermodynamics, which is something of a problem.