If you're already familiar with the command line, or you are comfortable setting up a new pi SD card, and following a script, here's the quick install guide!
sudo apt-get update
sudo apt-get upgrade
#
# Expand your partition to fill your SD card
# Make sure you're booting into the console
#
sudo raspi-config
sudo update-rc.d lightdm disable
#
# Install Node.js
#
sudo apt-get install git htop rng-tools
wget http://node-arm.herokuapp.com/node_latest_armhf.deb
sudo dpkg -i node_latest_armhf.deb
#
#
#
echo "Enabling hardware random number generator"
sudo modprobe bcm2708-rng
echo "add bcm2708-rng to /etc/modules"
echo "Now you have /dev/hwrng !"
sync
#
# Install DFU-Util
#
sudo apt-get install libusb-1.0-0-dev
wget http://dfu-util.gnumonks.org/releases/dfu-util-0.7.tar.gz
tar xvf dfu-util-0.7.tar.gz
cd dfu-util-0.7
./configure
make
sudo make install
#
# Install the Spark-CLI
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sudo npm install -g spark-cli
#
# Setup a project folder
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sudo mkdir /spark
sudo chown pi /spark
sudo chgrp pi /spark
cd /spark
git clone https://github.com/spark/spark-server.git
cd spark-server/js
npm install
node main.js