WordSmith Tools is a collection of corpus linguistics

Corpus linguistics

Corpus linguistics is the study of language as expressed in samples or "real world" text. This method represents a digestive approach to deriving a set of abstract rules by which a natural language is governed or else relates to another language. Originally done by hand, corpora are now largely...

 tools for looking for patterns in a language. The software was devised by Mike Scott at the University of Liverpool and for versions 1 to 4 was sold by Oxford University Press

Oxford University Press

Oxford University Press is the largest university press in the world. It is a department of the University of Oxford and is governed by a group of 15 academics appointed by the Vice-Chancellor known as the Delegates of the Press. They are headed by the Secretary to the Delegates, who serves as...

. The current version is 5.0 and is available from Lexical Analysis Software Ltd. The tools include a concordancer

Concordancer

A concordancer is a computer program that automatically constructs a concordance. The output of a concordancer may serve as input to a translation memory system for computer-assisted translation, or as an early step in machine translation....

, word-listing facilities, a tool for computing the keywords

Keywords

Keywords are the words that are used to reveal the internal structure of an author's reasoning. While they are used primarily for rhetoric, they are also used in a strictly grammatical sense for structural composition, reasoning, and comprehension...

of a text or genre, and a series of other utilities e.g. to convert text files from one format to another or to make multiple changes in many text files, to examine the format of text files, to download texts from the web, etc.