ESP32 is the newest version of the now famous Espressif ESP8266.
Now running on two years old the ESP8266 originally was launched as a serial to WiFi adapter but took on a life of its own with developers earning its place in hundreds of modules and IoT projects.
Modules based on the new ESP32 chip are starting to appear with Seeed Studios ESP3212 Wifi Bluetooth Combo Module the first on the market for $6.60. A technical reference manual can be found here: https://espressif.com/sites/default/files/documentation/esp32_technical_reference_manual_en.pdf
