It claims to be "Fast search for very large numbers of keys in a body of text", but this module is about three times slower than just using a regular expression like the one formed by list2re in Data::Munge, and it does not tell the position of the words in the string or the number of times they were found.
The interface is baffling. You put in a hash with keys and then it sends you back a hash with the same keys, except the keys of the return value are only for the words which matched. Why not just use a list, or return something useful like the position of the text in the string?
It also, for some reason, duplicates Perl's hash function within itself, complete with a keys and a values method.
Although it was last updated in 2010, the module claims that at one point a lot of people were using it. Maybe Perl regular expressions were slower in 2001 or whenever this module's heyday was, but in 2017 this module may no longer be relevant or useful.