# NodeMCU Documentation NodeMCU is an [eLua](http://www.eluaproject.net/) based firmware for the [ESP8266 WiFi SOC from Espressif](http://espressif.com/en/products/esp8266/). The NodeMCU *firmware* is a companion project to the popular [NodeMCU dev kits](https://github.com/nodemcu/nodemcu-devkit-v1.0), ready-made open source development boards with ESP8266-12E chips. ## Up-To-Date Documentation At the moment the only up-to-date documentation maintained by the current NodeMCU team is in [English](en/index.md). It is part of the source code repository (`/docs` subfolder) and kept in sync with the code. We encourage you to help transferring the outdated translations (see below) into the repository. ## Outdated And Sparse Documentation The following translations are based on outdated documentation, use them with caution. The links point to the [NodeMCU wiki on GitHub](https://github.com/nodemcu/nodemcu-firmware/wiki). - Chinese, [中文](https://github.com/nodemcu/nodemcu-firmware/wiki/nodemcu_api_cn) - Russian, [русский](https://github.com/nodemcu/nodemcu-firmware/wiki/nodemcu_api_ru) - Spanish, [español](https://github.com/nodemcu/nodemcu-firmware/wiki/nodemcu_api_es)