Your best bet is to search these forums for "mime". you'll find much info about it.
here's one thread that describes howto associate mimetypes.
There is also a howto on the oesf wiki about mimetypes.http://www.oesf.org/forums/index.php?showtopic=12070&hl=mime
Also in that thread is mention of a script that was never included on the Zaurus that handles mimetypes for you. qtopia-addmimetype
I was curious, and googled for that script, and found it.
I'll paste it here, in case someone can use it.
if [ -z "$NEWTYPE" -o -z "$EXT" ]
echo >&2 "Usage: $0 <mimetype> <extension>"
echo >&2 " eg. $0 application/foobar foo"
# Can ash do this? If not, use sed.
grep -w $EXT $QPEDIR/etc/mime.types |
read TYPE EXTS
if [ -z "$TYPE" ]
if grep -q "^$NEWTYPE[ ]" $QPEDIR/etc/mime.types || grep -q "^$NEWTYPE$" $QPEDIR/etc/mime.types
if sed -e '/^'$T"\\/"$S'[ ]/ s/$/ '$EXT'/' <$QPEDIR/etc/mime.types >$QPEDIR/etc/mime.types.new ||
sed -e '/^'$T"\\/"$S'$/ s/$/ '$EXT'/' <$QPEDIR/etc/mime.types >$QPEDIR/etc/mime.types.new
mv $QPEDIR/etc/mime.types.new $QPEDIR/etc/mime.types
echo >&2 "Internal MIME type update error"
echo "$NEWTYPE $EXT" >>$QPEDIR/etc/mime.types
elif [ "$TYPE" = "$NEWTYPE" ]
#echo "Already done"
echo >&2 "$EXT already assigned to $TYPE"
I also found this Japanese mimetype tool, but never figured out how to use it.
All the dialogs, etc. are in Japanese. I have attached it here
Mimetypetool requires Ruby be installed in Sharp/Cacko.
Install ruby-qte_0.5.1-1_arm.ipk first to avoid dependency warning when installing ruby_1.8.0-1_arm.ipk
For your Tree!Explorer question, you have to have the registered version for images and files to be launched from it's interface.