pure js implementation of pigpio
npm install js-pigpio      
A pure JS library for interacting with Raspberry Pi GPIO using the
pigpio daemon (for pwm, servo control, etc)
The pigpio library uses direct memory access (DMA) to allow you to sample
the GPIOs up to 1,000,000 times per second. It also makes it fast enough to
give you PWM and servo control on all GPIOs simultaneously. The servo
waveforms are accurate to a few microseconds.
This code is based off of the python library
included with the pigpio download.
For managed access to the GPIO using javascript checkout js-gpiozero.
It's early days and a work in progress!