Aardvark's English forum: Fill-in-the-blank and multiple-choice quizzes.
Activities for ESL Students: A project of The Internet TESL Journal that includes free quizzes, exercises and puzzles for students.
Agendaweb: Includes online grammar, vocabulary, and listening activities.
EFL Reading: Features ghost, horror, adventure and football stories, links and glossary. Includes exercises to test comprehension and build vocabulary.
El Rebumbio: Features interactive self-correcting exercises grouped by skill.
English 4U: Has explanations how to use grammar combined with exercises and includes information and exercises about countries and cities, crosswords, irregular verbs exercises, texts and quizzes.
English @ WSL: Contains English language quizzes, a listen while reading section, and a dictionary.
English Exercises Online: Interactive exercises at all levels.
English Grammar Online: Offers exercises, explanations (grammar, writing), games, literature, teaching materials and information on English-speaking countries
English Ladder: Offers 20 levels of interactive English quizzes. Requires free registration.
ESL Discussion Center: Discussion forums for students of English as a Second Language. Organized by topic.
ESL Partyland: Provides many interactive quizzes, discussion forums and topic-based learning pages for students. On the teachers side, lessons and printable materials to use in class.
ESL Projects: Featuring instructions and topics for English projects.
ESL Teaching through Songs: Worksheets using English songs to teach grammar elements. Includes articles about TESOL teaching (UK based).
ESL Wonderland: Includes interactive listening, reading, and grammar integrated activities.
Fiesta English: Features grammar and vocabulary tests for Spanish speaking students, a Spanish-English vocabulary by category section and trivia quizzes.
Global English Kids: Online English lessons in Korean, Chinese and Japanese. Practice speaking, grammar, writing and learn new words. [Windows only]
Interesting things for ESL Students: Includes quizzes, games, and puzzles to help students learning English.
Internet Picture Dictionary: Picture dictionary with interactive activities for ESL learners.
Kids Corner 4 English: Has grammar explanations, listening comprehension and find the mistake exercises, dictations, and stories.
Learn English with British Council: Includes games, songs, stories, various topics, and printable material.
Learning Resources from CNN San Francisco: CNN stories with simple English, audio, video, and activities.
Longman Teens Community Website: Includes a chat room, interactive language reviews, and advice page.
Mado's English School: Contains EFL and ESL games, grammar and vocabulary exercises for secondary students.
Mrs. Ferguson's Favorites: ESL Games and Activities: Provides links to language learning games for elementary through high school students.
Multicultural Kids: ESL students from all parts of the world tell about their homelands.
Quizzes at The ESL Area: Online quizzes organized by topic, grammar, and quiz type.
Randall's ESL Cyber Listening Lab: Listening practice for students through self-grading quiz pages, comprehension quizzes, and study material. Requires RealAudio or Divace.
Renda English Corner Forum: A forum where native Chinese users can practice their English.
Tower of English: Internet ESL guide with activities, tests, resources and fun ideas.
WordMania: Includes brainteasers, trivia, crosswords, hangman, word search activities, kids' area, classic books and links for ESL students.