Hi David,
Thanks for asking.
Yes, I'm absolutely committed to that. The URL is a permalink and there seems to be no issue with Brown keeping
papl.cs.brown.edu up. It's just a virtual host tied to a set of static files.
We haven't really made plans to open source the book. That's a bit of a big build task. Also, there are some authors we would trust more than others to make modifications… Not a statement about any individual, but I've seen too many pirated copies of my books on unsavory sites, and I worry about this turning into another channel for abuse (which very obviously is not you!).
I wonder if you're aware of the successor,
DCIC. I'm guessing you are, and the dropping of the second half of PAPL is why you are asking. We
are continuously working on and improving DCIC, so if there are fixes in the first half, perhaps you can tell us and your students can use DCIC instead?
As for the second half: I'm in the midst of a serious re-think of the PL portion (which is derived from my earlier book,
PLAI). This year a lot of things have fallen into place and I'm finally writing up a draft of the third edition of PLAI. "Sadly", of course, that will be in Racket, not Pyret. But that's because we get to really
exploit Racket's support for languages: see, for instance,
this paper, which is now implemented
in Racket. Furthermore, I'm doing a fair bit of research that is driving the construction of the third edition. So, in return for the Racket use, you'd gain both an actively-maintained book
and one that is driven by research into PL pedagogy.
Shriram