Khan AcademyWith a library of thousands of videos and practice exercises covering everything from arithmetic to physics, finance, and history, the Khan Academy is on a mission to help you learn whatever you want, whenever you want, at your own pace.
lingro: The coolest dictionary known to hombre"lingro's mission is to create an on-line environment that allows anyone learning a language to quickly look up and learn the vocabulary most important to them." Enter a website address to make all of words on the page clickable. Click on words you don't know and a definition will pop-up.
The Firefly Five Language Visual Dictionary by 