FOLDOC is a computing dictionary. It includes definitions of acronyms, jargon, programming languages, tools, architecture, operating systems, and so much more of the vocabulary you would expect to find in a computer dictionary.
W3Schools is an educational website for learning coding online. Initially released in 1998, it derives its name from the World Wide Web but is not affiliated with the W3 Consortium. W3Schools offers courses covering all aspects of web development.