Arduino
For Arduino users, we recommend the Adafruit Neopixel Library.
Teensy 3
For Teensy3 users, we recommend Paul Stoffregen's updated Adafruit Neopixel Library.
mbed
The PixelArray library works with several mbed microcontrollers (using SPI)
Raspberry Pi
The rpi_ws281x library works with native Raspberry Pi GPIO pins, using DMA and PWM.
Espruino
Supported by the Espruino firmware.