Just a very pragmatic request for recommendations of software tools to construct B-Trees and to visualize them. The software should be highly didactic, so not necessarily be able to build trees with thousands, or even hundreds, of nodes.
It should offer several options to build such trees: in one shot, e.g. with minimal or maximal height, or successively according to the standard splitting algorithm. Of course, it should be possible to set the type k of the tree, and the software should gently warn, if the combination of height and type doesn't allow to construct a tree for the data given.
Optional the software should also give answers on questions like how to calculate the maximum or minimum height given a type k, or the other was around.
Also, optionally, the software may be asked to restructure a given input tree, so that it becomes optimally balanced and/or most compact or most sparse.