Interesting site.

Ok, I stand corrected- I was clearly thinking of trioxane and not hexamine. I had a LOT of surplus trioxane tabs stored at one point, and they had deteriorated (and disintigrated) into nasty stuff after 15 years or so... and, reading the various warnings, I disposed of them and the stove I had used them in, and resolved not to do that again.

What I had matches the photos of US miltary trioxane tabs on the site, not the photos of US military hexamine.

The evidence seems compelling that Esbits are at least largely hexamine. I've never used (or, for that matter, even seen) any of the other brands of Hexamine listed- but I know that Mamod is a big name in the steam-model circles, and I find it interesting that the box describes the tablets as "waxed". That would explain the surface texture, which leads many to believe that the tablets are wax-based. I wonder if it also explains thier long shelf life?