From MathWeb

The OMDoc specification fixes the OMDoc MIME type to application/omdoc+xml, which is in accordance with RFC 3023. (See also the IANA MIME type registry.)

Subversion

Problem: When accessing Subversion over WebDAV (Apache), OMDoc files should be served with the correct MIME type.

Setting svn:mime-type

… does not work, as Subversion considers OMDoc files binary then :-(
But note, for obtaining a diff of such files, you can do svn diff --force

Configuring Apache

is possible, see below.

1. Add a line application/omdoc+xml omdoc to the file references by TypesConfig in the main Apache configuration file.
2. Make Apache map file names to MIME types correctly on virtual hosts (the OMDoc svn is on a virtual host)!

       <Location /repos>
               # maps server/repos/X to SVNParentPath/X
               DAV svn
               SVNParentPath /var/svn/mathweb
               # ...
               # MIME types
               ModMimeUsePathInfo on
       </Location>