Good question! I have quite a few Pi sipping small amounts of power here, so... Web server, mail server, gopher server, key server, NTP server, SMS gateway (wit

Good question! I have quite a few Pi sipping small amounts of power here, so... Web server, mail server, gopher server, key server, NTP server, SMS gateway (with SMS hat), NTP client network reference clock (Pi Zero), MQTT server, Flightaware box, PiHole, XMPP server.