Guide to Grammar and Writing — online tutorials on grammar and English usage. From subject-verb agreement and use of articles to exercises in parallel structures and argumentative essays
Lexicons of Early Modern English (LEME) — searches and displays word-entries from monolingual English dictionaries, bilingual lexicons, technical vocabularies, and other encyclopedic-lexical works, 1480-1755
Skeptic’s Dictionary — combating pseudoscience and outrageous claims wherever they may be found
Symbols.com — online encyclopedia that contains everything about symbols, signs, flags and glyphs arranged by categories such as culture, country, religion, and more