This module implements the Swedish stemming algorithm to improve Swedish-language searching with the Drupal built-in search.module.
It reduces each word in the index to its basic root or stem so that variations on a word (e.g. "klok, klokare, klokast" or "klockan, klockans") are considered equivalent when searching. This generally results in more relevant results.
While this module does improve Drupal search for Swedish language sites I highly recommend you take a look at Apache Solr Search Integration if you want really good search.