MHonArc can process mail messages to create a set of indexed html pages. Threaded and chronological indices can be generated, and messages can be added incrementally to an existing archive. A `standalone' mode is also supported for quick conversions of individual messages to HTML without adding them to the index. MIME attachments in mail messages are handled. MHTML is also supported. The program is highly customizable and is well documented. See URL "http://www.oac.uci.edu/indiv/ehood/mhonarc.doc.html" for more information.