  MAID is a unitary isobar model for a partial wave analysis of pion photo- and
electroproduction in the resonance region. It is fitted to the world data and
can give predictions for multipoles, amplitudes, cross sections and
polarization observables in the energy range from pion threshold up to W=2 GeV
and photon virtualities Q^2 < 5 GeV^2. Using more recent experimental results
from Mainz, Bates, Bonn and JLab for Q^2 up to 4.0 GeV^2, the Q^2 dependence of
the helicity couplings A_{1/2}, A_{3/2}, S_{1/2} has been extracted for a
series of four star resonances. We compare single-Q^2 analyses with a
superglobal fit in a new parametrization of Maid2005. Besides the (pion) MAID,
at Mainz we maintain a collection of online programs for partial wave analysis
of eta, eta' and kaon photo- and electroproduction which are all based on
similar footings with field theoretical background and baryon excitations in
Breit-Wigner form.
