On gold
A stable currency, ideally, should be based on commodities. A dollar bill should represent about a dollar's worth of real wealth.
Gold or other precious metals were used for this most often because they are easy to figure out, easily divisible, reasonably rare, non-perishable, and it's easy to store a lot of wealth in a small space.
I see no reason some agreed-upon mix of other similar commodities wouldn't work as well.
Of course, governments like floating currency, because it lets them print money when they want it. Even borrowing has to be based on real production of wealth somewhere down the line.