I've been working on a Uniscribe interface to VisualWorks Smalltalk off and on for the last two weeks or so. One of the frustrating things for me so far, is the lack of a good post-doc resource to go to for help with this stuff. There's the MSDN docs, which are OK, but when you have questions beyond that, I have as of yet, not found any of the resources I'm used to using for this kind of thing, such as mailing lists, etc. And the amount of "tutorial" style pages out there is pretty small. So I thought I'd at least leave a trail of breadcrumbs here.
There is of course the Uniscribe Reference MSDN Docs.
Another valuable resource I found was Uniscribe: The Missing Documentation & Examples, a post written by one of the folks working on Chrome, once upon a time.
The other thing I discovered recently, is that where there are OpenType variants of UniscribeFunctions, you want to use those. For example, use ScriptShapeOpenType() instead of just ScriptShape().
Do I have a working binding between VisualWorks Smalltalk and Uniscribe? At a limited level, yes. I can deal with the standard kinds of Text emphases (#bold, #italic, #family, etc). Even #color. I'm not yet using any of the line breaking abilities (so it all comes out on one line). What can't I deal with... any string that results in more than one item. An item, in Uniscribe speak, occurs everytime the the writing system changes. So if you mix arabic and english, you get separate items for each range. But even more common, you get changes on any english punctuation. So the string 'abc,xyz' actually produces 3 items, one for the 'abc', one for the ',', and one for the 'xyz'. And currently... something isn't right with my interface when this happens. Item one is displayed correctly, but not the following items. When I figure it out, you can be sure there will be a followup post here.