Currently being developed in Visual Studio on Windows, thus it is currently distributed with a solution. You should be able to simply load the repo into Visual Studio using the solution. Then all you need to do is run using the Play button.
If you want to go for it. There is no real philosphy behind this project yet, so add on as you see fit. The standard is C++17. Ultimately, Thomas should be able to handle sprite sheets / tile sets (bit maps) and simple 3D graphics, as well as font/text rendering. In the future a GUI may be added as well.