Board won't show on one of my computers
My Ruggeduino stopped showing up as a serial device under El Capitan (10.11.6). I was able to fix this by installing/updating the VCP drivers for Silicon Labs USB devices available here:

https://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx

After installing the Mac driver the Ruggeduino shows up as SLAB_USBtoUART and works fine with the Arduino GUI.