"This site is about Arc, a new dialect of Lisp. It's unfinished, but usable, so we decided to release what we have so far. The current version compiles into MzScheme and structurally is as much a skin on MzScheme as a separate language. For example, Arc's read is MzScheme's, and so are Arc's numbers and math operations. But from the average programmer's point of view, Arc is no more similar to Scheme than any two Lisp dialects are to one another. Arc is designed above all for exploratory programming: the kind where you decide what to write by writing it. A good medium for exploratory programming is one that makes programs brief and malleable, so that's what we've aimed for. This is a medium for sketching software."