Would it be possible to open-source parts of the PenFlip code? The exporters are the part that could benefit the most, IMO. For example, there is an active bug report that is of particular concern to my project that has been an issue for more than a year and a half (tables do not show up exporting to Word) - I could have had this bug fixed in a week with access to the source, and I would of course be more than happy to share that solution back to the community. I'm sure many people have their own pet bugs plus the coding ability to fix them.
And with Penflip's support of git, open source seems like it'd be a natural fit.