Commentpress is an open source theme and plugin for Wordpress 3.3.1 or later designed to enable readers to contribute comments to each paragraph of a text and display those comments in the margins. Commentpress turns a text into a conversation, whether a blog or a fixed document such as an essay, book or article. It may also be used to add a gloss or annotations to a document. This tool is also available for BuddyPress and BP Group Blog.

NLTK 2.0 (Natural Language Tooklt) is a free, open source collection of Python modules, linguistic data and documentation for research and development in natural language processing and text analytics, with distributions for Windows, Mac OS X and Linux. It offers a platform for building Python programs to work with human language data, and integrates a guide to programming fundamentals.

The brat rapid annotation tool is an online environment for collaborative structured annotation of texts. It can be run in a browser (optimized for Chrome and Safari) or downloaded for local installation. It can be used for a variety of annotation tasks, from identitifying natural language entities to chunking to adding metadata.