The software package KANT V4 for computations in algebraic number elds is now available in version 4. In addition a new user interface has been released. We will outline the features of this new software package.
Using a new regulator bound we determine unit groups and class groups of the 289040 quintic algebraic number fields with absolute discriminant less than 2 × 10 7 (totally real fields), respectively 5 × 10 6 (other signatures). We list significant data.