www.nodemcu.com, and https://github.com/nodemcu/nodemcu-firmware/wiki/nodemcu_api_en
Ard--uino-like hardware IO
Advanced API for hardware IO, which can dramatically reduce the redundant work for configuring and manipulating hardware.
Code like ard--uino, but interactively in Lua script.
Nodejs style network API
Event-driven API for network applicaitons, which faciliates developers writing code running on a 5mm*5mm sized MCU in Nodejs style.
Greatly speed up your IOT application developing process.
Lowest cost WI-FI
The Development Kit based on ESP8266, integates GPIO, PWM, IIC, 1-Wire and ADC all in one board.
Power your developement in the fastest way combinating with NodeMCU Firmware!
USB-TTL included, plug&play
10 GPIO, every GPIO can be PWM, I2C, 1-wire
FCC CERTIFIED WI-FI module(Coming soon)