  We present an approach to non-uniform complexity in which single-pass
instruction sequences play a key part, and answer various questions that arise
from this approach. We introduce several kinds of non-uniform complexity
classes. One kind includes a counterpart of the well-known non-uniform
complexity class P/poly and another kind includes a counterpart of the
well-known non-uniform complexity class NP/poly. Moreover, we introduce a
general notion of completeness for the non-uniform complexity classes of the
latter kind. We also formulate a counterpart of the well-known complexity
theoretic conjecture that NP is not included in P/poly. We think that the
presented approach opens up an additional way of investigating issues
concerning non-uniform complexity.
