Setup a Build Environment
For developing RIOT, basically all you need is a working C/C++ (cross-)compiler and make. Depending on you target platform you eventually need additional tools for interfacing with your board, as for example OpenOCD or similar.
To create this environment there are many options, the most easy ones are discussed below.
The most straight-forward way to develop RIOT is to install the tool-chain. Have a look here and follow the link to the family of your targeted platform for more information on the tool-chain needed and instructions for installation.
Option two is to install and configure an Mint Linux to use as a virtual machine. Have a look here for more information on how to create and configure a VirtualBox VM.
RIOT comes with a ready-to-use docker file to set up a docker container ready for RIOT development. Have a look here for more information.