On macOS, install the Arduino IDE using [homebrew](http://brew.sh/) [cask](https://caskroom.github.io/) with `brew cask install arduino` or download the application from [the official website](https://www.arduino.cc/en/Main/Software) and move it to your `/Applications` folder.
On Linux, your distribution's package manager probably includes the Arduino IDE, but it may be an out of date version. If your distribution installs a version of Arduino before 1.6.3 or so, you'll need to install the Arduino IDE following the instructions [on the wiki](https://github.com/keyboardio/Kaleidoscope/wiki/Arduino-Setup-Linux).
If you install Arduino into some place that's /not/ `/usr/local/arduino`, you'll need to set the `$ARDUINO_PATH` environment variable to the directory containing the `arduino` and `arduino-builder` binaries.
You can customize your keyboard's key layout and LED effects by modifying the `Model01-Firmware.ino` file in the same directory as this README. Model01-Firmware.ino is a computer program written in 'Arduino C'. You can find documentation about Arduino C at https://arduino.cc.
From time to time, you may want to pull the latest version of this firmware from GitHub. To do that, navigate to the Model01-Firmware directory in your shell and pull the latest code.
```sh
cd Model01-Firmware
git pull
```
After that, you'll want to update the Kaleidoscope libraries.
### MacOS
```sh
cd $HOME/Documents/Arduino/hardware/keyboardio/avr