This is a WordPress plugin that fixes a WP bug: "pretty" search URLs containing encoded spaces (e.g. http://example.com/search/boo%20radley) are not correctly decoded and so do not work. The bug is covered at http://core.trac.wordpress.org/ticket/13961 This bug will eventually be fixed (hopefully during the second half of 2011). After that this plugin will no longer be needed. For details, see http://www.thunderguy.com/semicolon/2011/06/08/search-fixer-wordpress-plugin/