What’s the point of [Arc][1]? Infix-syntax [Dylan][2] is a much, much better language, especially once you add in the changes and features from the [Dylan Design Notes][3] and the infix version (but keep the prefix syntax). Really, Dylan is pretty much the Ultimate Lisp in a lot of ways.
Arc is essentially `(decr Scheme)` with a couple of interesting additions to try and make up for the downsides. Downsides like a lack of international character support (what decade is it again?!) and an unhygienic macro system.
[Dylan — as designed in the **early 1990s**][4] — really is `(incr Scheme)`. It’s essentially Scheme re-hosted atop an enhanced CLOS-like object system. With the prefix syntax, it’s even very Scheme-like in actual use.
So, yeah. If you’re interested in Arc, check out Dylan. It’s a better language, and there have been implementations available for 15+ years.
PS – The original Dylan had a [`
[1]: http://www.arclanguage.org/
[2]: http://www.opendylan.org/
[3]: http://amigos.rdsathene.org/other/prefix-dylan/design-notes/home.html
[4]: http://amigos.rdsathene.org/other/prefix-dylan/book.annotated/preface.html
[5]: http://amigos.rdsathene.org/other/prefix-dylan/book.annotated/ch12.html#unicode-string-class0