When trying to determine "authorship" of an article, one possible method would be to "count" the number of edits for a given article. This is particularly important when trying to determine who the "principle author" of an article might be when giving citations of the article, or for formal copyright registration.
In short, a quick count "tab" or "button" in the history page would then count each user's contributions in a fashion like this:
User1 (20 edits)
User2 (15 edits)
User3 (7 edits)
126.96.36.199 (3 edits)
To get "fancy" you could even try to eliminate counts from reversions (or even reversion wars), especially to eliminate giving credit to vandals. A simple implementation would only require a simple count.
Another further enhancement would be to list the timestamp for the last edit for each author on a particular article.
The main purpose of this is to extract the names of all authors for a particular article.