The comments on here are down right now. They run on Cusdis — open-source, on their free hosted tier, and the most lightweight option I could find. I’ve used a few commenting systems over the years — FastComments, Disqus, that lot — and Cusdis was the leanest by a distance: no tracker payload, no account wall, just a textbox. The catch with lightweight-and-free is that when the hosted instance falls over, my comments fall over with it, and there’s nothing to do but wait.

Which is fine. Comments were never the point of this place, and only a handful of posts ever get any. But it’s a tidy illustration of what you sign up for when you lean on someone else’s free service: you’ve outsourced a feature and its uptime. I could write my own in an afternoon — it’s a form, a table, and a bit of moderation — but then the uptime would be mine too, and that’s the part nobody misses until it’s theirs.