I've been involved in IoT development for about five years. One year ago, I posted the following photo of some IoT device platforms:
Here's what I wrote at that time:
C.H.I.P. - for those who want a desktop interface (which you don't need for IoT devices). Would be better if it used HDMI display instead of composite.
Onion Omega 2+ - just got it, maybe similar to C.H.I.P.
Raspberry Pi 0 - relatively large power demand; missed the boat by not having built-in wifi.
TinyDuino - overpriced; wifi optional/extra (and very expensive).
Intel Edison - small power demand; great hardware and software; overpriced.
RedBear Duo - software is slow to mature; overpriced.
ESP8266 - this is the powerhouse behind the IoT revolution!
ESP32 (prototype) - this is the future.
One year later...
C.H.I.P. is now in breadboard-friendly form factor, but at $16.
Omega 2+ is very stable, but is not breadboard-friendly. It has not made it into a lot of commercial products.
There is now the Pi Zero W, which has wifi and BLE, and still $5!
TinyDuino and RedBear Duo haven't changed much.
Intel Edison is no longer in production.
ESP8266 is still going strong and can be found in more and more places.
ESP32 is now commonly available - the future is here!
There are other IoT device platforms, like the BeagleBone, the Particle Photon and Electron, and the various boards from Pycom. We also have new transport mediums, too, like LoRa and SigFox. From a hardware standpoint, IoT developers have a banquet of choices!
Things are good on the software side, too. Most of these boards can be programmed in multiple languages. Over the last five years, whole IoT ecosystems (middleware, backend, and "analytics pipeline") have evolved! It is a great time to be involved in IoT development!
