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.
It's not for everyone. In fact, Arc embodies just about every form of political incorrectness possible in a programming language. It doesn't have strong typing, or even type declarations; it uses overlays on hash tables instead of conventional objects; its macros are unhygienic; it doesn't distinguish between falsity and the empty list, or between form and content in web pages; it doesn't have modules or any predefined form of encapsulation except closures; it doesn't support any character sets except ascii. Such things may have their uses, but there's also a place for a language that skips them, just as there is a place in architecture for markers as well as laser printers.
To the extent we can influence whatever customs are associated with Arc, we'd like to propose three principles.
Number one, expect change. Arc is still fluid and future releases are guaranteed to break all your code. In fact, it was mainly to aid the evolution of the language that we even released it.
Second, we'd like to encourage a sense of community among Arc users. If you have a question or a suggestion, share it with everyone in the forum. And if you know the answer to a question you see in the forum, help out whoever posted it by replying. Be nice; if someone's being a dick, don't let the anonymity of forums tempt you to reply in kind.
And finally: It's not a coincidence that we wrote a language for exploratory programming rather than the sort where an army of programmers builds a big, bureaucratic piece of software for a big, bureaucratic organization. Exploratory programming is the fun end of programming, and we hope that will be the guiding principle of the Arc community.
