TFieldedText is a component which allows you to easily: generate and parse Fielded Text Files (eg. CSV files); and create and edit Fielded Text Meta files. For more information about the Fielded Text standard see http://www.fieldedtext.org
IronMeta is an implementation of Alessandro Warth's OMeta metaprogramming system in C#. It provides a packrat parser generator that generates parsers for Parsing Expression Grammars that operate on arbitrary streams of objects.
Voikko is a spell checking, grammar checking, morphological analysis and hyphenation system. Spell checkers are available for multiple languages, other features for Finnish only.