  This article reviews the current works on ultra-compact double-degenerate
binaries in the presence of magnetic interaction, in particular, unipolar
induction. The orbital dynamics and evolution of compact white-dwarf pairs are
discussed in detail. Models and predictions of electron cyclotron masers from
unipolar-inductor compact binaries and unipolar-inductor white-dwarf planetary
systems are presented. Einstein-Laub effects in compact binaries are briefly
discussed.
