As for lojic's question about why not just use PLT Scheme? That's a very good question. Personally, I find Arc has a lot of negatives compared to PLT Scheme, and the only positive I see is the macro system isn't confusing like Scheme's. Arc also provides the excitement of exploring new territory, but I think I've about exhausted that.
What about the rest of you? Why use Arc instead of Scheme? (Maybe this should be a top-level question?)
The reasons I use Arc (well, not these days, due to incredible lack of time, but...) :
- excellent macro system (even if mzscheme seems to have a "dirty" defmacro too),
- the empty list is the false boolean,
- the syntax (particularily  and :) is really a great improvement,
- I never built webapps that fast (and with so much fun),
- my list is close to almkglor's, but he's before me in the leaders' list, and I'll never catch him, so I can't follow him on this point :)
Now, sure, PLT is an excellent language/environment. But it's waaaaay older, that helps. Actually, if today I was given the opportunity to program in a Lisp of my choice (for work I mean, not for fun), I'd use Arc for a basic webapp and mzscheme for almost everything else.
Ditto. I especially like the fact that, because there are so few people working on it, I actually have a chance at making a difference. Not a very big chance, since as yet I'm still a noob, but it's still something to hope for ;)
I thought it would be cool to be part of new Lisp community also, and it may eventually develop into that, but it's increasingly seeming like just a pet project of pg's that may or may not develop into something more. That's not a criticism - I think it was generous of pg to open source Arc and invite folks to participate, and he's been straightforward with his intentions. It's just a slightly different project than I expected initially.
I'm also a Lisp newbie. If I was already experienced in Common Lisp or Scheme, I might be more interested in investing more time with Arc to learn something new, but at this point, I'm simply looking for the best Lisp to learn. Given that I primarily develop web based software, you'd think Arc might be the one; however the ease of creating simple web apps is offset by the lack of other stuff I need and the question of long term viability.
So, learning PLT Scheme seems like a reasonable course of action because I expect I can bring most of that knowledge back to Arc if it gains more traction. Who knows, if developing web apps with PLT Scheme becomes too painful, maybe I'll just switch back to Arc and give it a few months of learning.
I agree with your comments, and those above, and I actually think it's a huge strength of this project and why I remain interested. I think way, way too much stuff in the software community is focused on DO LOTS OF STUFF RIGHT AWAY GET IT DONE YESTERDAY WAAAAHHHHHHHH FASTER FASTER FASTER!!! That may be the right way to start a company, but it's a really crappy way to build a "one-hundred year language".
I like the fact that this project is moving slowly, and that the community (from newbies like me to pros like Tilton) has time to try things and reflect, and not in internet time.
I'm 36. I've already learned and thrown away about 3 different major development ecosystems in my career. I accept that I'll continue to do that in order to pay my mortgage, but in my own time, when I'm actually programming for fun, I want to hitch my wagon to something that will actually have some lasting value. And Arc (or at least something very similar) is the best-looking option to me at the moment.