  Recent analytical and numerical solutions of the above systems are reviewed.
Discussed results include: a) exact construction of the supersymmetric vacua in
two space-time dimensions, and b) precise numerical calculations of the
coexisting continuous and discrete spectra in the four-dimensional system,
together with the identification of dynamical supermultiplets and SUSY vacua.
New construction of the gluinoless SO(9) singlet state, which is vastly
different from the empty state, in the ten-dimensional model is also briefly
summarized.
