  We evaluate all next-to-maximal helicity violating (NMHV) six-gluon
amplitudes in type I open superstring theory in four dimensions, at the disk
level, to all orders in alpha'. Although the computation utilizes
supersymmetric Ward identities, the result holds for all compactifications,
even for those that break supersymmetry and is completely model-independent.
Together with the maximally helicity violating (MHV) amplitudes presented in
the previous work, our results provide the complete six-gluon disk amplitude.
