March 5, 2026
Schema drama alert
Relax NG is a schema language for XML
XML’s rulebook gets love for simplicity—and roasted for errors
TLDR: RELAX NG is a standard way to validate XML files, praised for its simple, readable compact format. Commenters love the design but bash libxml2’s cryptic errors and question XML’s hype-era relevance, making this old standard feel both useful and dated—and very memeable.
RELAX NG, the official rulebook that checks whether XML files are shaped correctly, is back in the spotlight—and the comments are messy. It’s standardised by big bodies like OASIS and ISO, and fans love its simple design and the readable compact format. But the crowd is split.
User masklinn delivered the most dramatic take: they’ve used it tons and still like the model, yet say libxml2’s validation errors are “absolutely useless,” turning every mistake into a late‑night scavenger hunt. Meanwhile, jitl waved the nostalgia flag for the compact syntax—dropping a link—and joked it “reminds me of TypeScript,” a programming language famous for tidy types.
Then came the big mood: was XML just a 90s/00s buzzword? Jitl poked the bear, implying it didn’t live up to the hype, and the thread flirted with the eternal meme—XML vs JSON cage match. Some cheered “simple rules, readable syntax,” others rolled eyes at cryptic tooling and ancient vibes. The jokes wrote themselves: “RELAX NG? Not when the errors hit.” In short, the tech is solid, the standards are official, but the community is vibing between cozy nostalgia and frustrated debugging—and it’s oddly entertaining. Even the homepage’s 2014 timestamp became a running gag
Key Points
- •RELAX NG is a schema language for XML emphasizing simplicity, a compact and an XML syntax, and support for namespaces, mixed and unordered content.
- •RELAX NG was developed within OASIS by the RELAX NG Technical Committee and is standardized as ISO/IEC 19757-2 within the DSDL family.
- •The language draws on TREX (James Clark) and RELAX Core (MURATA Makoto) as its foundations.
- •An extension project for RELAX NG (Version 2) has begun in ISO/IEC JTC1/SC34/WG1; Version 1 remains Part 2 of ISO/IEC 19757.
- •The site lists tutorials (2001, 2003) and specifications from OASIS and ISO (2003, 2006 amendment, 2008 second edition), plus links to software, schemas, and test suites.