Dave,
I guess I have not been poking around OpenSourceCMS long enough to see that it is PHP-centric. My bad. I do think that Jeffrey's post is a good summary of "what is wrong" and also a good basis for taking a stock of where OACS stands viz. these. Your summary reply is good, although subjective (<wink/>).
Also, OACS is more than just a CMS, hence, probably, not all of his points apply. On the other hand, "task-based documentation" is a good one that would probably apply to many-many applications, both OSS and not...