what is format of Numbers file ?
How can I make Numbers file from other languages like c# ?
Files with extension ".numbers" as saved from the Application Numbers is really a zip file which contains a plist, and xml file, a tiff and other files. It is easy to look at the contents by taking an existing Numbers file, changing the extension to .zip, then uncompressing.
I have NOT been successful at changing anything in the zip, then rezipping, then renaming the file back from .zip to .numbers.