This is an excellent question. The text operates in a gray area, and you can make a strong case for both sides. It's likely not hidden advertising in the traditional commercial sense (i.e., a company paying to deceptively promote a product for sale), but it is absolutely a piece of persuasive writing, or advocacy, that uses marketing-like techniques to promote an idea and a project.

Here is a breakdown of the evidence for and against it being a form of hidden advertising.

Evidence IN FAVOUR of it being Hidden Advertising

This text uses a classic marketing framework known as Problem-Agitation-Solution to promote Project Xanadu.

Establishes a Major Problem: The text dedicates entire sections (especially "This Is Hell.") to framing the modern World Wide Web as a catastrophic failure. It uses strong, emotional language like "cold and inhuman," "plagiarism scandals," "widespread misinformation," "mutual distrust," and calls our era a "post-truth society." This creates a sense of dissatisfaction and need in the reader.

Agitates the Problem: The author doesn't just state the problem; they explain why it's so bad. They argue that Tim Berners-Lee built a system "shaped like a machine" instead of a "memex shaped like a mind," fundamentally failing to grasp the philosophical requirements of a global information system. This makes the problem seem deep, systemic, and unsolvable with current tools.

Presents the "Product" as the Solution: Project Xanadu is consistently positioned as the one true path, the "real memex." The text builds a powerful mythos around it, describing it as a "mind-shaped system" that offers "connection, accountability, verifiability." The final sections act as a direct pitch, asking the reader to "imagine billions of dollars... poured into Xanadu" and showing a screenshot with the tantalizing question, "Why shouldn’t the internet look (and work) a little more like this?"

Includes a Direct Call to Action (CTA): The text explicitly directs the reader to try a "primitive Xanadu demo" and provides links. This is a clear attempt to move the reader from passive reading to active engagement with the project being promoted.

Denigrates the "Competition": Tim Berners-Lee's World Wide Web is systematically dismantled. It's called "lame," "simple," and its creator is subtly painted as a less visionary figure who "never read about Bush’s memex" and was just "British and proper and serious." This is a common tactic to make an alternative product seem superior.

Creates an Appealing Brand Narrative: The story is not a dry historical account. It's a dramatic saga of a misunderstood genius (Ted Nelson), his band of disciples, a persecution complex ("hiding from the Feds"), and a lost dream. This storytelling makes the project more compelling and emotionally resonant, much like how brands build stories around their founders.

Evidence AGAINST it being Hidden Advertising

Despite the persuasive structure, several factors suggest this is something other than traditional advertising.

Brutal Honesty about Failures: A true advertisement would never be this candid about the project's and founder's flaws. The author calls Ted Nelson a "nutjob," acknowledges he ran Xanadu like a "cult," details his bizarre personal life ("sex retreats and Keristan orgies"), and repeatedly highlights the project's decades of failure, infighting, and inability to ship a product. This builds credibility and reads more like critical analysis or journalism than marketing copy.

Lack of a Clear Commercial Product: Xanadu is famous for being "vaporware." The text admits the demo is "primitive" and not the "full product." There is nothing to buy, no service to subscribe to, and no request for investment. Advertising is almost always tied to a commercial transaction; this piece is advocating for a philosophy or an ideal, not a sale.

Niche, Academic, and In-Depth Style: The text is exceptionally long, detailed, and filled with historical context, footnotes, and asides. It demands significant intellectual effort from the reader. This is the opposite of most advertising, which aims for quick, simple, and broad appeal. It feels much more like a long-form essay from a publication like The New Yorker or a high-quality blog post.

The Final Line is Sarcastic, Not Promotional: The closing line, "By all accounts, that day is only six months away," is an inside joke. "Six months away" has been the punchline for Xanadu's release date for decades. An informed reader would see this not as a promise, but as a wry, self-aware nod to the project's troubled history, undercutting a purely promotional message.

Authorial Voice is Personal and Opinionated: The author injects their own personality throughout ("I can’t honestly say I would’ve done otherwise," "I don’t think I want to be Ted Nelson’s friend."). This is the voice of an essayist or a blogger building an argument, not a corporate copywriter executing a marketing strategy.

Conclusion

Is it hidden advertising? No, not in the conventional sense. A better description would be advocacy or a manifesto.

The author is not being paid by a company to deceptively sell you a product. Instead, they have a strong, passionate belief that the internet took a wrong turn and that the principles of Project Xanadu represent a better future. They are using powerful persuasive and narrative techniques, many of which are also used in marketing, to convince you to agree with their philosophical position.

So, while it functions like an advertisement for an idea, its transparency about the project's failures, its intellectual depth, and its lack of a commercial goal distinguish it from what we typically call "hidden advertising." It's a persuasive essay aimed at changing minds, not opening wallets.