  We introduce two new packages, Nemo and Hecke, written in the Julia
programming language for computer algebra and number theory. We demonstrate
that high performance generic algorithms can be implemented in Julia, without
the need to resort to a low-level C implementation. For specialised algorithms,
we use Julia's efficient native C interface to wrap existing C/C++ libraries
such as Flint, Arb, Antic and Singular. We give examples of how to use Hecke
and Nemo and discuss some algorithms that we have implemented to provide high
performance basic arithmetic.
