This tool illustrates a method of visualizing a 4-dimensional space through 4 views of dimension 3. Two examples are developed: - a 4D maze. The "maze" tab allows you to discover a first person view 4D labyrinth. The help page and the first tutorials allow you to get used to the interface. This is a presentation video (switch on English subtitles) https://youtu.be/gU-HD63ahyM. - a 4D object viewer. The "viewer" tab gives you access to a visualization of a space in 4 dimensions. It is possible to select various solids and to move, turn and observe them in projection or in section. Watch this video https://www.youtube.com/watch?v=vEKzjGhCmTI for a first introduction and few other examples on https://www.youtube.com/playlist?list=PLD5yLeJQ0t9jaMS5JX2JNoa2NN0_p05kK. This idea is described in this document https://hal.archives-ouvertes.fr/hal-03192641. It extends the principle of technical drawing to a space of dimension 4. Takad means 'space' or 'region' in Breton.