  Lie brackets or Lie affgebra structures on several classes of affine spaces
of matrices are studied. These include general normalised affine matrices,
special normalised affine matrices, anti-symmetric and anti-hermitian
normalised affine matrices and special anti-hermitian normalised affine
matrices. It is shown that, when retracted to the underlying vector spaces,
they correspond to classical matrix Lie algebras: general and special linear,
anti-symmetric, anti-hermitian and special anti-hermitian Lie algebras
respectively.
