JS/UIX; a complete virtual UNIX machine that runs entirely in JavaScript using DHTML. Well, not entirely complete; the realistic-looking executable files in
/bin, upon closer inspection, have sizes of 'n/a', and are basically façades for JavaScript pixie dust that does what they are meant to; also, the shell doesn't actually support any scripting commands. However, you can create and access files, and it even has a mostly usable implementation of
vi.