Languages

Resources mainly relating to East Asian languages.

Dictionaries

Chinese/English Dictionary and MDBG English to Chinese dictionary – Online Mandarin–English dictionary
Thesaurus Linguae Sericae – An Historical and Comparative Encyclopaedia of Chinese Conceptual Schemes
Jim Breen's WWWJDIC – Japanese-English, with example sentences and kanji lookup
NAVER 사전 and Daum 사전 – Korean - English - Chinese - Japanese dictionaries with Chinese characters
CEDICT, EDICT, and CC-Canto – Downloadable Mandarin, Japanese, and Cantonese–English dictionaries in EDICT format.
CHaracter Information Service Environment – Maintains a list of kanji and their constituent components
GlyphWiki – A wiki describing various shapes and variants of Chinese characters.
POPjisyo – A web portal that adds translations to Japanese, Korean, Chinese and English terms in web pages
rikaichan and RikaiXUL – Two plugins for Mozilla Firefox used to look up Japanese words in a web page
Unihan – Unicode's database of Chinese characters.

Texts and video

Chinese Text Project – An online digital library of pre-modern Chinese texts
溫故知新 Wengu zhixin – Chinese classics & translations
青空文庫　Aozora Bunko – Texts in Japanese (out-of-copyright books etc.)
*プロジェクト杉田玄白* – More texts in Japanese
ICDL - International Children's Digital Library – Children's books in several languages
Crunchyroll – A video streaming site specializing in Japanese animation

Textbooks and learning materials

MIT OpenCourseWare – Chinese and Japanese
Pinyin Practice
Pinyin - Chinese Pinyin Table
sci.lang.japan FAQ – Answers to frequently asked questions from the newsgroup sci.lang.japan
Japanese for the Western Brain
Tae Kim's Japanese guide to Japanese grammar
"My Korean" and "Korean Through Active Listening" – Korean textbooks with audio and online video, available for free download
Korean Studies at Sogang

Discussion forums and chats

2ch – An anonymous Japanese message board

Howtos

Internationalization in Linux – Guide to managing IMEs and language settings in Linux.
Declan's Guide to Installing and Using Microsoft's Japanese IME