OmniGraffle is a proprietary diagramming application: https://en.wikipedia.org/wiki/OmniGraffle https://www.omnigroup.com/omnigraffle/ It has a custom file format based on the XML-based Apple plist format: https://en.wikipedia.org/wiki/Property_list The extension of OmniGraffle files is .graffle and the files may be optionally gzipped. There is a C library for reading Apple plist files here: http://www.libimobiledevice.org/ Here are a few samples available at the URLs below: https://github.com/riscv/riscv-isa-manual/tree/master/src/graffles/ https://github.com/martincr/omnigraffle/blob/master/User%20journey.graffle https://github.com/martincr/omnigraffle/blob/master/Funnel%20diagram.graffle https://github.com/charlax/OmnigraffleScripts/blob/master/ResetPrototype/Example.graffle
David, does adding support for this format sound okay to you? If so, please confirm the ticket.
I doubt I'm going to work on it myself, but, in general, why not... Btw, all texts are saved as RTF documents, which makes the task considerably harder (well, I can imagine requiring external support for RTF import, which would probably be reasonably doable in LibreOffice, but would complicate the integration anyway).