Karp is the lexical search system of Språkbanken. The graphical interface of Karp is found here.
If you would like to learn how to use Karp, you can find exercises in Swedish here.
Lars Borin, Markus Forsberg, Leif-Jöran Olsson, Jonatan Uppström (2012): The open lexical infrastructure of Språkbanken, in Proceedings of the 8th International Conference on Language Resources and Evaluation : May 23-25, 2012 / eds. Nicoletta Calzolari, pages 3598-3602