I just downloaded the Raspberry Pi (rate) image from the PirateBox webpage. I received a zip file containing only one file, called raw_arch_image (no extension).
The zip itself is called ArchLinuxARMv6-2015-06_PirateBox1.0.2_rpi_1.0.5.img.zip
There is apparently supposed to be a disk image somewhere in this, how do I write it to an SD card?