The mate desktop is not recognized in xdg-open. This leads to the wrong - if one at all - application being opened when e.g. opening a file from the browser. See http://keramida.wordpress.com/2013/03/18/mate-desktop-support-for-xdg-open/ for a patch
Support for mate was added awhile ago, starting with: http://cgit.freedesktop.org/xdg/xdg-utils/commit/?id=b961235b197647d6649ef3d48d7cc2cecafe3d47
This was in 2011. It's 2014 now, and no public release contains this patch. This is sad.
Yes it is, Im hoping to step up to help make a new formal release soon. So far, I've only contributed fixes here and there.
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