> Matrix reinvented the wheel as a rubber-tyred metro. On paper, it provides real benefits, such as climbing steeper inclines, which are then used to aggressively advertise and lobby local governments to buy in. But in the end, the municipality gets locked into a single vendor.

I stumble upon Matrix from time to time, but Jabber I haven't really seen anywhere in the past decade after my internet friends moved to IRC. Are there any bigger communities still using it? Back in the days Facebook Messenger was backed by it, so maybe there's still some bigger entity using it as a backbone for something?