Postgres is a modern and powerful relational database that also supports storing of json, xml and object relationships. Postgres has a strong open source community behind it and is actively maintained. Postgres is also highly scalable database with drivers for all the major programming languages.
In this workshop we are going to use Heroku Postgres, a database on demand service that requires no local installation.
Alternatively, you can use a local instance of Postgres if you are happy to run it on your laptop.