XML: a technology at the heart of our daily lives

In my last article, I mentioned XML several times, perhaps assuming that all users had a basic understanding of it. Rereading it, I realised that an introduction to XML was needed for non-technical users, those who use XML every day without realising it, when they open a document, check the weather, place or receive an order online, or issue a digital invoice. XML works silently behind the scenes.

But what exactly is XML and why should it matter to non-techies? I will try to explain it in simple terms.

XML stands for eXtensible Markup Language, a way of organising information in a format that is easy for both people and computers to understand, helping different applications communicate and exchange data using a common language. Put simply, XML is a digital container that clearly labels information.

For example, this is a shopping list in XML format:


<groceryList>
  <item>
    <name>Bread</name>
    <quantity>1 loaf</quantity>
  </item>
  <item>
    <name>Milk</name>
    <quantity>2 litres</quantity>
  </item>
</groceryList>


Labelling helps computers and software understand exactly what each piece of information means.

In a hyperconnected world like ours, where apps and systems share data, XML allows that data to move between very different systems, such as credit card management apps and online shops. Without a common language like XML, communication between these systems would be much more complicated and slower, or even impossible.

So, XML is integrated into most everyday activities, even though it is completely hidden from users:

• All documents created by all office suites use XML, in some cases to facilitate transparency and interoperability, and in other cases to create a hidden layer of complexity with the aim of preventing transparency and interoperability.
• All apps that provide weather forecasts obtain updates by reading XML data issued by weather agencies.
• Almost all e-commerce applications use XML to manage communication between the website, the payment system, the bank and the shipping service.
• All blogs and news sites use XML to automatically transmit new content to readers.

XML is clear and easy to read because it organises data in an orderly manner with labels that are understandable to both humans and computers; it is flexible, as it is not limited to a single type of information and can be customised for different scenarios, from cooking recipes to flight schedules; and it is compatible with all platforms.

To appreciate the value of XML, you don’t need to have a deep understanding of the language, just know that it exists and that – when used properly, as in the case of the ODF format – it has the potential to help users achieve and protect their digital sovereignty.

Of course, it is equally important to know that XML can be used in exactly the opposite way, as is the case with Microsoft 365’s OOXML format (and previously Office), to limit users’ digital sovereignty and perpetuate lock-in through artificial file complexity.

In summary, XML is a silent enabler that ensures that users’ apps, services and data all speak the same language.

The next time you open a document, check your favourite news site or follow an online delivery, remember that XML is working silently behind the scenes to ensure that everything runs smoothly. And try to imagine a digital world without XML, where a single company controls the data and, through it, the users.