Rafael,
Nice paper. I think the finished version will be a useful bit of literature to help explain OACS.
A few points:
1. You don't really explain what an enterprise framework is and how it differs from an application framework
2. You should define web application framework in section 2 rather than later on in the document. In fact, you define web application framework two different ways, once in section 3.1 and again in section 4.
3. On a related note: "Exhibiting more than web-readiness, OpenACS is a web-centric application framework designed specifically for interaction with users via the web environment." Sounds like marketing gobbledy-gook to me. I would think that every web-centric application framework had been designed specifically for interacting with users via the web. What is the difference between a "web-centric application framework" and a "web application framework" (which you use in the next sentence). Also, and it may make more sense to someone who reads your reference 3, I'm not so sure about this "web-readiness" criterion. It would seem to me that any web application framework would by definition be web-ready.
4. Slightly new topic: the distinction between an application framework that is "general in focus" and one that is developed to solve the "specific challenges of a particular application domain" seems a little suspect to me. What exactly is a framework that is "general in focus"? A library, perhaps? How does an application framework that "solve[s] specific challenges of a particular application domain" differ from an application? My point, basically, is that you seem to be implying that if something is geared towards a particular domain, it is not general.
5. The majority of your concluding section is concerned with one paragraph in the body of your 13 page paper. There is certainly a fine line concerning how much information to put in a conclusion, especially for a short paper. My feeling, however, is that you need to assume that a reader who has been given your paper is going to look at the intro and the conclusion. Therefore you need to briefly repeat the definition of a (web) application framework, list the key criteria, and indicate how OACS satisfies all/some of them.
6. Another point about the conclusion: I wouldn't call Tomcat a platform. Rather, it's an implementation of a platform. At least in theory, an application that runs on Tomcat should run on any of several other implementations such as Resin, etc.
Finally, as this is just a draft, it's not worth going into, but there are a number of grammatical, etc. problems that should be cleared up before releasing the document. I would be more than happy to edit the penultimate version when you get there.
Matt