If people change their own article, no problem. Though
re-moderation is an issue. Somebody could write a
reasonably small article on PASCAL, and then alter it
planting a binary bomb or doing something silly to it.
If people want to "edit" somebody else's article, it
should be allowed by all means, and should be linked
to at the top/bottom (?) of the article with a breif
description of what the author edited. These should
also be moderated to prvent it from turning into a
discussion board. You'd end up with threads full of
arguments, name calling etc. It would be a farse and
ruin the whole informative tone of the resource.