Raycasting is used in the Wolfenstein part.
Raycasting is a rendering technique to create a 3D perspective in a 2D map. Back when computers were slower it wasn't possible to run real 3D engines in realtime, and raycasting was the first solution. Raycasting can go very fast, because only a calculation has to be done for every vertical line of the screen. The most well known game that used this technique, is of course Wolfenstein 3D.
(source)I'm not sure what the technique used for the racing game is called, but it's basically the same as the old Lotus games.
Something about resizing and stretching sprites. I was too bored to read through the code and learn how it works in details.
The third part is indeed 3D. The dots are stored in space and the objects positions are calculated out from them.
More precisely some kind of a Perspective Projection is used to calculate the objects screen coordinates.
I'm babbling and you are probably wondering why I know so much about the internal workings of the systems.
The reason is that I have the source code. You can download the open system here:
http://www.hbgames.org/myonosken/3DengineV5Open.rar