Todo list (maybe in this order)
Wish list (not ordered)
- provide Crypto-API support for HSSF
- Split scratchpad/ooxml into bundles for H/XSLF, H/XWPF, H/X....
- Provide .msi support - I have already a contribution from Sebastian S.
- Provide wmf support - I've already started it, but with the plethora of gdi calls, I suspended it for something more interesting ... see wmf render branch
- provide ppt <-> pptx converter to complete common_sl
Common SL implementation notes
- Javadocs only in common interface, otherwise (normally) just use @Override - see  (there was even a better stackoverflow page, but can't find it right now ...)
- Design of the common interface and it's implementations - see 
- Replace Array methods (e.g. getShapes(), getSlides()) with List counterparts - fits better to generics, and also to the Iterable interface - (todo: link stackoverflow page)
- new: HSLF text handling is now based paragraphs and runs - so it fits nicely to XSLF
- Also empty TextParagraphs are returned - i.e. only a TextHeaderAtom without TextBytes/CharsAtom
- new: the drawing classes now support shape fill
- check differences in org.apache.poi.hslf.usermodel.TestBugs for tests: bug41071,bug42520,bug43781,bug45776,bug47261,bug56260,bug41246b,bug42474_1
- need to rework the generics common interfaces, replace typed methods by class parameters ... I've already tried several times, to make it easy to use and either ended in the generics hell or had not really clean method definitions
- Changed text property handling: using null value instead of -1 for left margin & others. So properties can be removed, via setting as null and null (instead of some default value) will be returned, if the property is not defined.
- Color calculation/transformation is not inside XSLF classes anymore, but the stored values are returned - for transformed colors, use DrawPaint.applyColorTransform instead
- TODO: a common interface or factory to create shapes