The National Archives of Australia has licensed Xena under the GNU General Public License version 3 (the GPL3). Under the terms of the GPL, you are permitted to modify and redistribute the Xena code. You are free to copy and re-use both the source code and the finished Xena product.
The task of digital preservation, regardless of the method used, will always involve working with data in ways likely to cause changes. We are confident that the treatment of digital data by Xena is an effective means of digital preservation, but we don't just ask you to take our word for that. Our source code is available for all to see so that anyone may verify the actions of Xena.
We believe that conducting our software development in an open and public way will better serve to demonstrate the transparency and authenticity of our method of digital preservation. In addition, making our code and documentation freely available has made it easy for others to collaborate with us on further development of the software.
The following table lists the preservation formats we have adopted for various file types. These preservation formats are all open formats (see What makes a format open? for more information).
Open Document Format (ODF)
ISO/IEC 26300:2006 http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=office#odf11
Portable Document Format (PDF)
ISO/IEC 32000-1:2008 http://www.adobe.com/devnet/pdf/pdf_reference_archive.html
Adobe PDF was officially released as an open standard on July 1, 2008, and published by the International Organization for Standardization as ISO/IEC 32000-1:2008
A list of the file formats supported by Xena can be found on the Supported Formats page of the Xena website.
The following are four key characteristics of open formats.
The full specification of any standard on which a format is based should be publicly available without restriction.
Standards on which formats are based should be developed by a community rather than by a single vendor or interest group. The National Archives of Australia takes a keen interest in standards development and is represented on many international standards committees.
For a format to be truly open, multiple separate software implementations created by different authors or organisations should exist. Duplication of standards is bad, but duplication of implementations is necessary for the health and longevity of a standard. As an example, if you want to buy a power outlet in Australia (a General Purpose Outlet), you can choose from at least the Clipsal and HPM brands when you make your purchase. You don’t need to worry about which will be compatible with your electrical equipment though, because both manufacturers adhere to the same power outlet standard.
There should be no intellectual property licensing or patent restrictions on the use of a format. Determining who owns the intellectual property associated with a standard can be difficult and confusing. Always aim for formats that declare no licensing restrictions.
When Xena normalises a file, it is converted into a new Xena file with the extension .xena. These files contain the normalised file as well as any extra information relevant to the normalisation process.
You can view these files and export the normalised file via the Xena Viewer.
From within Xena:
Alternatively, load the Xena Viewer as a separate application:
Linux - execute the script:
OS X - run the Xena Viewer application
When you start Xena, it loads all the plugins available under the Xena/plugins directory.
If you attempt to normalise a certain file format and the corresponding plugin is either not in the plugins directory or does not exist (for example video), Xena will only binary normalise the input file. In such cases, the Normaliser column of the Normalisation Results is either blank or displays one of the following:
Xena will binary normalise any files that are already in a preservation file format (such as PNG). This is because the files are already in the desired format and do not need to be converted.