Slightly tangential, but stigmergy is a fascinating topic. If anybody recalls Ant Colony Optimization from a couple of decades ago, it was based on this: https://en.wikipedia.org/wiki/Ant_colony_optimization_algori... -- I was researching it for a bit, and while the reality never matched the hype, people actually shipped a few related projects in the areas of logistics. It eventually went nowhere, I suspect as computers became more powerful and other, less heuristics-based approaches worked better.

I still think stigmergy is under-appreciated, especially in the context of decentralized systems. The main reason centralization is such a powerful force is because you can do so, so much more with data aggregated in one place (e.g. discovery, spam filtering, and "big data" in general.) But if we want to achieve similar capabilities at similar scale in fully decentralized systems, stigmergy might be a powerful tool.