The software used is WsprryPi, https://github.com/JamesP6000/WsprryPi. It's a transmit-only package, no receiving involved.

The antenna will be something like this: http://www.moxonantennaproject.com/construction.htm, built with wire and four telescopic fibreglass fishing poles. Since the feedpoint for this design is in free space I'll either have to use a short length of co-ax and mount the Pi at the centre, or more likely construct a lightweight waterproof enclosure and mount it at the feedpoint.