KASH/KANT is a computer algebra system for sophisticated computations in algebraic number fields and global function fields. KASH is freely available. All algorithms implemented in KASH are available through an interpreted pascal-like programming language.
Citation:
@misc{kash,
author = {M.~E. Pohst et al},
title = {The Computer Algebra System {{KASH/KANT}}},
howpublished ={{\tt http://www.math.tu-berlin.de/\~{ }kant}}}
}