The web server firmware opens up a ton of possibilities with CGI scripting. When booting up in AP mode, you can even connect the ESP8266 to another access point right from the your browser.

Thanks to affordable hardware like the ESP8266 one of those things a modern web browser can do is sense and control the real world.

For this example during a session of Sunday night hacking an Adafruit ESP8266 Feather HUZZAH is used to control NeoPixels or a relay. In short, no external server, gateway, service, computer ...