ServiceStack was used to create a RESTful Web Service accessible by URIs not files with extensions. AutoConfiguration of mod_mono added all of the mime types and file extensions but not the simple path (URI) to a web service.
Solution: I added these lines to my httpd.conf to create a virtual path and to configure it to work with mod_mono.
Alias /info "/var/www/html/myService"
MonoApplications "/info:/var/www/html/myService"
<Location /info>
SetHandler mono
</Location>
Now http://localhost:8080/metadata
works just fine.