Patrick Michaud on the reasons behind Author variables:

I have trouble with the idea that PmWiki can automatically designate the "original author" -- many times pages are created as simple placeholders, which other authors then come and fill in. So, I think $Creator is probably better name than $Author for this, if we were to add it. But overall I think it's a mistake to try to get PmWiki to automatically determine "primary" authorship. Sometimes pages are completely reworked; and some authors will start deleting and re-posting pages just so they can get a perceived status or ego associated with some "primary author" designation. I think it's better if the appropriate credits for contributions appear in the content (either as prose, signatures, citations, or directives), than to have PmWiki impose a particular model on its authors.

Lastly, PmWikiPhilosophy #1 is "favor writers over readers", and somewhat fundamental to that concept is that any reader can also be an author, thus $Author instead of $User or $Reader. While I recognize this idea of "readers are authors" isn't universally true for many sites that will use PmWiki, as well as an extreme case of wishful thinking, the truth is that in PmWiki the only way someone gets a value into the $Author variable is to actually *be* an author.

(In case any are wondering, "authorship" and "identity" are two different things in PmWiki. The variable used to track the "reader" or login is $AuthId, and it really stands for "authenticated identity", as opposed to "author identity" or "author".)

Radu?: The idea of 'readers as authors' is somehow negated by the existence of separate 'read' and 'edit' password sets.

I somewhat disagree. First, the 'read' password has nothing to do with this-- a read password doesn't separate a population into readers and authors, it separates them into readers and non-readers.

So, it's only the edit password that tends to separate things -- but even there, an edit password doesn't have to be site-wide. The edit password can be used (and often is used) simply to say "you can author any page on the site except the ones protected by this password". Generally the edit password is used as a security measure, not as a classification or caste system.

But in the final analysis, just because PmWiki promotes a particular view of the world doesn't mean it has to be totally consistent with it, or enslaved by it. In the "favor writers over readers" case, I'm rebelling against the traditional web maintenance architecture that limits pages to only one author (typically called the "webmaster"), and constrains everyone else to submitting their changes through that author. The philosophy isn't saying that everyone must be an author, it is saying that we should remove the barriers that prevent more people from becoming authors.

See also: Cookbook:PageCreator - recipe allowing to store, access and modify a Creator variable.