BlockSCAD is a good option for youngsters who may develop an interest in programming and parametric modeling, as it's based on OpenSCAD, a text based modeling description "language." My experience with BlockSCAD is mostly frustrating but that's because I learned OpenSCAD before I became aware of BlockSCAD. For the youth, it's a good start due to the simplicity and intuitive aspect of the coding. Other resources use a similar GUI that make BlockSCAD valuable in accepting other, similar types of software.