William Whitaker's Words - Latin-to-English and English-to-Latin translation program provided by the University of Notre Dame
Latin Wikipedia - Latin language version of Wikipedia with over 100,000 articles
Grammatica - In-depth Latin grammar study guide
SurfaceLanguages - Flashcards, sound clips, and vocabulary games with ecclesiastical Latin, legal Latin, proverbs and maxims, and general phrases
Getting Started on Classical Latin from The Open University - General introductory course with grammar, pronunciation guides, and quizzes; readable in browser or downloadable in eBook format
Latin The Way The Romans Learned It - C.J. Cherryh, former Latin teacher and author, begins with an outline of the Latin sentence structure for the basis of study of the language
Latin courses and translation features from Mango are offered free through Columbus Metropolitan Library; must have library card
Transparent Language is a complete language-learning system for independent learners of over 110 languages, including Latin. Transparent's Latin for English Speakers course consists of lessons including listening, speaking, reading, and writing practice.