mod_text2html is an Apache module.  It is written in C and was designed
to replace Apache's internal text/plain handler (the core handler found
in http_core.c).  It has a couple of key points.

1) It converts newlines to <BR>.

2) If it finds valid URLs it turns them in <A HREF> (and does
   a good job of trying to not muddle up HTML that has been flagged as
   text).

3) It converts '<', '>', and '&' to HTML entities.

4) Using the same method as the Unix file utility it
   determines if the file is text in the first place.  If it determines
   that it is not text it sends the files, but does so as
   application/octet-stream (so no nasty dumps of binary to the screen).