3 ms·HSL provides the bus, tram, suburban rail, subway and ferry system in the Helsinki metropolitan area.by tuukkah 9y agoHSL provides the bus, tram, suburban rail, subway and ferry system in the Helsinki metropolitan area.stevekemp 9y agoI've written a few toys that use their GraphQL API to show real-time displays of trams. Pretty neat system.tuukkah 9y agoThanks! Waiting for your MQTT integration ;-)