&gt; <i>this is Mozilla who have a large concentration of people familiar with browser technologies.</i><p>It does, but this is not the reason. Browsers have grown to contain a stellar collection of networking APIs (compared to the rest), and IoT devices depend on talking to each other. Indeed, the people at Mozilla working on this stuff know more about the nitty-gritty of the low-level than about standard Web development. The API is for the users.