I just discovered this little gem in my collection and am very tempted to put it into use on my #Harlequin128K#ZXSpectrum clone sometime.
It is a unified BASIC dialect called BASICODE 2 developed by the dutch national radio service in 1984. It contains BASICODE 2 interpeters for almost all common microcomputer systems of that era as well as BASICODE 2 example programs and games.
I suppose it was part of a series of tutorial shows on how to program. But I'm not 100% sure as I'm german, not dutch.