Mac OS 10.10 or higher
Windows 8.1 or higher
20GB+ of free hard disk space*
4GB+ of RAM
Fully updated version of Google Chrome or Firefox.
Chrome is the preferred browser but they both work well.
*20GB sounds rather high for recording a podcast. This is because the browser can only use a percentage of the free disk space. Having 20GB free should ensure that there is at least 2GB available for recordings.