hi, I use a PC with W10 and a friend has PC with Linux,
before I install Calligra Suite I ask about if files Calligra generated in one OS, may be opened in the other OS
thanks in advance
Eugenio

In general, files can be freely shared between OS's without problem. So long as both computers are using software compatible with the file format being shared then it should all work.

There should be no issues with Calligra on one OS opening up documents created by Calligra on another OS.
Presumably, you will be sharing files in the Open Document format (i.e. MyWordFile.odt, MySpreadsheet.ods, etc.), the default in Calligra and other office suites. You should be able to open them up not just in Calligra but also in LibreOffice, OpenOffice, MS Office and a host of other installed and online office suites on whatever OS you may be using without problems (in practice, there may be some compatibility problems between different office suites, in particular around MS Office, though these days those should be pretty minor).

thanks a lot for your answer
Eugenio