You are probably
always going to want to do some per-customer
customization, and the bigger and more "enterprise" the application
and the customer, the more so. (Consider things like SAP deployments,
for example.)
Whether that customization takes place in the source code or not is,
to some degree, an implementation detail. But just hacking the code
is always the quickest easiest way to do it - at least at first. So,
the obvious first step is to get the best version control tool for
your code you can. E.g., ditch CVS and investigate Arch immediately.
That way, at least you won't be artificially pushed into non
code hacking methods of customization. And to me, that suggests that
your ultimate designed solutions will be superior, as you will be able
to learn from, e.g., refactoring 2 to 4 custom customer deployments
into one unified whole, once you've learned what's important from
experience.
However, I would never call code customization "Copy-Past-Modify".
This implies all the wrong stuff... You should probably call it the
"Customize Code and Refactor" approach, or something like that.
Frank, as far as the rest of your question about approach or
approaches to use... I don't know. You seem to have a good start on
thinking about possible ways to do it, and I lack hands-on experience
in this. Other helpful steps might be to:
Briefly describe of all the known per-customer customizations
you've ended up doing in practice.
Find out who else is using OpenACS to do SAP-like customized
independent deployments of vertically integrated integrations to
multiple customers. In other words, not fully custom functionality,
but (minor?) variations for each customer on a specific application
theme (e.g., "company intranet"). The only example I can think of
there off hand are the various dotLRN sites running at different
universities (except, they all tend to have OpenACS hackers on staff,
which changes things). Perhaps also that semiconductor thin films
equipment company that uses OpenACS - if they deploy OpenACS to
customer sites; I'm not sure whether they do or not.
