IPAL
The "IPA Lexicon of the Japanese language for computers" contains basic nouns, verbs and adjectives.
Japan Electronic Dictionary Research Institute
The EDR Electronic Dictionary was developed for advanced processing of natural language by computers, and is composed of eleven sub-dictionaries. Sub-dictionaries include a concept dictionary, word dictionaries, and bilingual dictionaries.
Japanese Dictation Toolkit
Free software repository for automatic speech recognition, sponsored by IPA (Information-technology Promotion Agency), Japan.
Juman
An extensible morphological parser for Japanese running on Windows and Unix.
Kakasi - Kanji Kana Simple Inverter
A language processing filter to convert kanji characters to hiragana, katakana or alphabetic characters (romaji). It may be helpful to read Japanese documents.