cue.language is a free library of Java code and resources for basic natural language processing emerging from the development of the Wordle word cloud tool and maintained by Jonathan Feinman of IBM's CUE Research Group. Its functions include tokenization, counting strings, detecting the script alphabet or writing system required to represent the text, guess the text's language and customizeable stop word detection.

TXM is a free, open source text corpus analysis environment. Its features include concordance, collocate search, frequencies based on the CQP full text search engine and statistical functions based on R packages. It can export results in CSV, XML or SVG format, and runs as a standalone desktop application in Windows, OS X and Linux environments, or as a web portal (download the leaflet for more).

Tesla is a virtual research environment for text engineering - a framework you can use to create experiments in corpus linguistics, and to develop new algorithms for natural language processing. Tesla is a client-server application, which can be used by individual researchers as well as by workgroups. The screenshot below shows the experiment editor of Tesla's Client application.

BLLIP Parser (or Charniak-Johnson parser) is a statistical natural language parser for analyzing text to determine its grammatical structure. Grammatical structures are provided in Penn Treebank format.