:I was curious. Here is what I found. Maybe this will help until something is incorporated into the article.   

  
 :Pipermail is the bundled message archiver that comes with Mailman. Even though it's bundled, it is fairly separable, although Pipermail is probably more like a parasitic twin than an equal. Mailman in fact, has a very simple interface for hooking in external archivers other than Pipermail, and many people e.g. use MHonArc.