All of MS Office supports some version of XML. (At least, Word and Excel both do.) This isn't to say that the XML spec is documented, but you might be able to reverse-engineer it by saving your powerpoint projects as XML and seeing what happens ... (Of course, if you do this, I'd highly recommend putting at least the spec on the Net so that others can benefit from it, if not making a CPAN distribution .......)
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We are the carpenters and bricklayers of the Information Age.
Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.