Forum OpenACS Q&A: OpenACS, Perl, and data model changes 3.x->4.x

For my own entertainment and use, and on the off-chance other people
are interested, I've been working on enabling access to the ACS data
model through Perl.  As such, I've been hacking on a limited set of
Perl methods to access the OpenACS 3.x data model.

Since these efforts essentially allow one to access the same OpenACS
database that the TCL code does, it's fairly obvious I'm going to end
up changing my code for 4.x, since I understand there are some
significant changes in the data model and API; I'd appreciate it if
the people hacking on 4.x could give me an idea of how radical the
change is likely to be, mostly so I can get a feel for how worthwhile
continuing to work with the 3.x API is.

(The Perl architecture, BTW, is a core of modules replicating the ACS
API, such as the comments procs, as a set of methods; I'll also look
at layering some HTML::Mason ports of the interaction pages.)

You should expect that you will have to rewrite everything when you transition from the acs 3.x data-model to the acs 4.x data-model.  Other than some basic conecpts, there is nothing in common between the two data-models.