to the format of the Wordpress plugin
[footnotes](https://wordpress.org/plugins/footnotes/) and back.
+Usage: `footnotes --to mmd|wp [--file $inputfile]`
+
+### mmm.pl
+
+`mmm` (*MIME multipart/alternative from Markdown*) can
+create a MIME `multipart/alternative` mail, containing a
+`text/plain` part (in Markdown) and a `text/html` part, from
+a Markdown file. Other mail headers (From:, To:, Subject:, ...)
+can be prepended from a template file.
+
+Usage: `mmm [--file $inputfile] [--headers $templatefile]`