  In this article, we present a new construction of evaluation codes in the
Hamming metric, which we call twisted Reed-Solomon codes. Whereas Reed-Solomon
(RS) codes are MDS codes, this need not be the case for twisted RS codes.
Nonetheless, we show that our construction yields several families of MDS
codes. Further, for a large subclass of (MDS) twisted RS codes, we show that
the new codes are not generalized RS codes. To achieve this, we use properties
of Schur squares of codes as well as an explicit description of the dual of a
large subclass of our codes. We conclude the paper with a description of a
decoder, that performs very well in practice as shown by extensive simulation
results.
