  We study the effect of electron-electron interaction on the charge and spin
structures at the edge of integer quantum Hall liquids, under three different
kinds of confining potentials. Our exact diagonalization calculation for small
systems indicates that the low energy excitations of \nu=1 ferromagnetic state
are bosonic edge spin waves. Instabilities of the ferromagnetic state with
altering confinement strength result from the softening of these edge spin
waves, and formation of edge spin textures. In \nu\lesssim 2 regime, exact
diagonalization on edge electron systems indicates that compact Hartree-Fock
states with different total spin always become ground states in some regions of
parameter space, and the ground states appear in between two compact states are
their edge spin waves. The initial \nu=2 instability is toward the compact
state with total spin 1. Larger systems are studied using a microscopic trial
wave functions, and some quantitative predictions on the edge instabilities for
a certain type of confining potential are reached in the thermodynamic limit.
