  This article gives a brief introduction to $q$-special functions, i.e.,
$q$-analogues of the classical special functions. Here $q$ is a deformation
parameter, usually $0<q<1$, where $q=1$ is the classical case. The main topics
to be treated are $q$-hypergeometric series, with some selected evaluation and
transformation formulas, and the $q$-hypergeometric orthogonal polynomials,
most notably the Askey--Wilson polynomials. Some newer topics as nonsymmetric
analogues and $q=-1$ limits will also be addressed. In several variables we
discuss Macdonald polynomials associated with root systems, in particular the
$A_n$ and the $BC_n$ case. The theory of elliptic hypergeometric series also
gets some attention. The occurrence of $q$-series in number theory and
combinatorics will be discussed. Finally we indicate applications and
interpretations in quantum groups, Chevalley groups, affine Lie algebras and
statistical mechanics.
