Japanese Studies: Dictionaries & Encyclopedias

Japan Knowledge (UT database)
Combined search of dictionaries and encyclopedias.

Rikai

Yahoo! Japan 辞書
A collection of Japanese-Japanese, synonym, Japanese-English, English-Japanese, Japanese-Chinese, and Chinese-Japanese dictionaries, new terminology, encyclopedia, and specialized terms including medical, politics, etc. Search individually or combined.

Kotobank
Language dictionaries and general encyclopedia

Goo 辞書
A collection of Japanese-Japanese, synonym, Japanese-English, English-Japanese, Japanese-Chinese, and Chinese-Japanese dictionaries, search individually or combined.

Jim Breen's WWWJDIC

Nihon Rekishi Chimei Taikei 日本歴史地名大系 (UT database)

Kokushi Daijiten Web 国史大辞典web (UT database)