The Lost Art of XML: Why It Still Matters

XML (Extensible Markup Language) has been declared "dead" more times than any other technology, yet it quietly powers the backbone of modern digital infrastructure. While developers flock to JSON for its simplicity, XML continues to dominate in sectors where reliability, validation, and complex data structures are non-negotiable.

This article examines why XML remains indispensable in enterprise systems, government standards, and international organizations. From NATO's operational protocols to financial data exchange, the "lost art" of XML is experiencing a quiet renaissance among engineers who value precision over convenience.

Large-scale organizations continue to rely on XML for mission-critical systems because of its strict validation capabilities. Unlike JSON, which prioritizes lightweight data exchange, XML's schema validation ensures data integrity across complex ecosystems.

Financial institutions, healthcare systems, and government agencies use XML because it can enforce data types, required fields, and hierarchical relationships. This level of structural rigor prevents errors that could cascade through interconnected systems.

Key advantages include:

• Comprehensive schema validation (XSD, DTD)
• Namespaces for avoiding element conflicts
• Extensive tooling and library support
• Human-readable structure for debugging
• Native support for complex metadata

These features make XML particularly valuable for long-term data storage and inter-system communication where data contracts must remain stable for decades.

International organizations like NATO have standardized on XML for critical operations because of its reliability in high-stakes environments. Military communications require data formats that can be validated, audited, and processed across diverse systems with zero tolerance for ambiguity.

XML's ability to embed metadata directly within data structures makes it ideal for complex documentation standards. Government procurement systems, intelligence databases, and diplomatic communications all rely on XML-based formats that ensure interoperability between different nations and agencies.

When lives depend on data accuracy, there's no room for the flexibility that JSON offers. XML's rigidity becomes a feature, not a bug.

The technology's backward compatibility ensures that systems deployed decades ago can still communicate with modern platforms, protecting billions in infrastructure investment.

While JSON has become the de facto standard for web APIs, it lacks several critical features that XML provides natively. JSON's simplicity comes at the cost of expressive power—it cannot natively represent complex relationships or enforce data types without additional validation layers.

Consider these limitations:

• No native support for attributes or metadata
• Weak typing system (everything is a string or number)
• No standard schema validation language
• Limited support for namespaces
• Difficulty handling mixed content

For simple data exchange, JSON's lightweight nature is advantageous. However, for complex business documents, regulatory compliance, or long-term archiving, XML's comprehensive feature set remains unmatched.

XML is experiencing renewed interest in microservices architectures where service contracts must be explicitly defined. Modern tools like OpenAPI and gRPC have borrowed concepts from XML's schema definitions to create more robust API specifications.

The technology is also thriving in document-centric workflows where content needs to be both machine-readable and human-editable. Publishing systems, legal document management, and scientific data exchange all benefit from XML's ability to mix structured data with free text.

Emerging use cases include:

• Blockchain smart contract definitions
• IoT device configuration files
• Digital identity verification systems
• Supply chain tracking protocols

These applications leverage XML's validation capabilities to ensure data quality at scale, something JSON-based systems often struggle with.

XML's "lost art" status reflects a broader shift in software development toward speed over stability. While this trend has accelerated innovation, it has also created vulnerabilities in systems that require long-term reliability.

Organizations that understand both XML and JSON can choose the right tool for each job. Hybrid approaches are becoming common—using JSON for real-time APIs while maintaining XML for data exchange and archival.

The key takeaway is that technology maturity matters. XML's decades of refinement provide battle-tested solutions for complex problems that newer formats are still learning to address. As systems grow more interconnected, the "art" of XML may become essential knowledge for the next generation of engineers.