Arduino NeoPixel library
A library to control one wire protocol RGB and RGBW leds like SK6812, WS2811, and WS2812 that are commonly refered to as NeoPixels and two wire protocol RGB like APA102 commonly refered to as DotStars.
Supports most Arduino platforms.
This is the most funtional library for the Esp8266 as it provides solutions for all Esp8266 module types even when WiFi is used.
Please read this best practices link before connecting your NeoPixels, it will save you alot of time and effort.
Adafruit NeoPixel Best Practices
For bugs, make sure there isn't an active issue and then create one.
Installing This Library (prefered, you just want to use it)
Open the Library Manager and search for "NeoPixelBus by Makuna" and install
Installing This Library From GitHub (advanced, you want to contribute)
Create a directory in your Arduino\Library folder named "NeoPixelBus"
Clone (Git) this project into that folder.
It should now show up in the import list when you restart Arduino IDE.