Eagle is a proprietary Computer Assisted Drawing (CAD) software for designing Printed Circuit Boards (PCBs) from Schematics to Gerber Files. This is the software that have primarily been used to design the MBHP PCB modules

You can find the official website here : http://www.cadsoftusa.com/

First, download the correct installer for your operating system at

http://www.cadsoftusa.com/download-eagle/

Follow the instructions to get the program installed

A serie of official Getting Started videos to be found here:

http://www.cadsoftusa.com/eagle-pcb-design-software/guided-tour/#c760