Generalizing the recent work on three-family Type I compactifications, we
classify perturbative Type I vacua obtained via compactifying on the T^6/Z_2 X
Z_2 X Z_3 orbifold with all possible Wilson lines. In particular, we
concentrate on models with gauge groups containing the Standard Model gauge
group SU(3)_c X SU(2)_w X U(1)_Y as a subgroup. All of the vacua we obtain
contain D5-branes and are non-perturbative from the heterotic viewpoint. The
models we discuss have three-chiral families. We study some of their
phenomenological properties, and point out non-trivial problems arising in
these models in the phenomenological context.Comment: 16 pages, revtex, minor misprints correcte
