[BRX]

But more important are legal issues. iRealPro will have to give permission but as far as I know they have never cooperated in making their data files accessible to other tools.

I agree there should be "legal safety".

But AFAIK there's no legal way for iRealPro to forbid using or programming tools to read and display the files. Especially because they have no rights to the contents of the files (the chords). Much like MS or Adobe can't forbid alternative viewers, converters or other programs using their formats like docx, pdf IRealPro shouldn't be able to forbid a viewer for the format.

Probably IRealPro even benefits from it bringing new customers since you can't create or edit the files or use the playback features.