Guides & Databases: English as a Second Lanugage (ESL): Online English Lessons & Tests

Find free & paid online, self-paced English courses.

ESL courses at EdX
A list of free ESL, TOEFL, and special topics course in English communication.
ESL courses at Coursera
A list of free and paid courses for learning English online, including special topics (ex. business English).

Transparent Language: Learn English
Transparent Language uses virtual flashcards to teach languages, including English. Choose from English immersion or a tutorial in 34 languages.
Learning Express Library: Adult Reading, Writing, & Speaking
Online exercises and tests to help you become a better reader, writer, and speaker of English at a basic adult level.
Learning Express Library: College Reading, Writing, & Speaking
Online exercises and tests to help you become a better reader, writer, and speaker of English at university level.