This generates a file with extension “fods“, which stands for “flat open document spreadsheet”. This is an XML file that can be loaded by LibreOffice and OpenOffice.org.
Availability
The default installation of LibreOffice / OpenOffice.org under windows will not be able to open this kind of file, and it is required to install a plugin.
Under linux, this plugin is installed by default and there should be nothing special to do to be able to read the generated file.
Compatibility
Every version of LibreOffice should be able to read those files. Otherwise this is a bug and should be reported. Every version of OpenOffice.org greater than 3.0 should work too.