To get this to work, copy the sub-folder "T2DMIT" into the texture packer "exporters" sub-folder. The location is different for each operating system. Once you installed the exporter, restart TexturePacker and you should see a "Torque 2D MIT" in the "Data Format" drop-down.

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* Windows *
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On my machine this was resulted in:

C:\Program Files (x86)\CodeAndWeb\TexturePacker\bin\exporters\T2DMIT

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* OS X *
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You will need to open the TexturePacker.app like a directory, then locate the exporters folder in Resources. Right click on TexturePacker.app, then click on Show Package Contents. This is the destination directory on my machine:

/Applications/TexturePacker.app/Contents/Resources/exporters