> Namespaces is something I consider a strong plus for XMPP. You may want to extend the data model at some point. You need a way to say "this is my extension, please ignore it". Or at least you need it if you want multiple implementations to work together.

Sure. The problem is that in every implementation I've seen, they're unreasonably hard to work with. Giving each extension its own key in a JSON object accomplishes the same, without breaking the native data model.

> map/filter/reduce etc is possible with XML. Scala does it. Other languages can do it to. It's purely depending on your language. Even JavaScript has better XML support than the language you're portraying here :-)

Yes, it's possible, but it's too hard. It always introduces more complexity when compared to standard deserialized JSON (in any language that can natively represent the JSON data types, which seems to be most).

In fairness....in some statically typed languages like Go, working with JSON isn't a ton of fun either, if you need things like optional fields.

Well, that’s not a limitation of statically typed languages, but a limitation of go.

Just like Generics.

Java, for example, does support Optional types similar to Haskell’s Maybe.

Haskell in supports them, too

Namespaces are a nice idea but almost all XML libraries make them unnecessarily cumbersome by requiring full specification everywhere. I sometimes wonder whether just fixing that would have made XML more popular after having seen so many people try to write something like a selector using the format in the document (ns:element), burning time until they learned that you have to use FULL_URL:element and in some cases even declare the namespace names you can't use.

No, it's not the biggest challenge but it's so transparently a case of conplete disregard for developer productivity that I've heard it mentioned by a lot of people as why they avoid XML.

> No, it's not the biggest challenge but it's so transparently a case of conplete disregard for developer productivity that I've heard it mentioned by a lot of people as why they avoid XML.

This is the core issue with XML/XMPP. UX simply doesn't seem to have ever been a factor when designing either of them - whether towards the developers or the end users.

Agreed: the XML and Java communities from the late 90s were plagued by the assumption that complexity was intrinsically good and that everyone wants to spend the time required to completely internalize a massive specification and all of its dependencies.

That is not at all a good characterization of what was going on. Do you remember what it was like before XML and Java? Could we have built anything on the scale of the web with CORBA?

(XMPP would've used JSON had it existed in 1998, fwiw.)

> Do you remember what it was like before XML and Java?

Yes – in particular, I remember liking the initial promise of XML 1.0 and then being disappointed as the initial simplicity was buried under layers of gratuitous complexity as the enterprise computing crowd jumped on board. Some neat ideas (e.g. XPath)

Similarly, my first database-backed web app was a Java servlet in 1996. I assumed it would become richer in the future but it was still pretty easy write and deployment was pretty simple at that point. Instead, the community chased off after more complexity (JavaBeans, the near-pervasive obsession with runtime configuration and the ensuing massive config files, nested abstraction layers, etc.) rather than focusing on basic developer productivity. We got massive piles of code like RMI (i.e. CORBA) before basic features like regular expressions, logging, etc.

> Could we have built anything on the scale of the web with CORBA?

No. We also failed, repeatedly, to do it with XML for reasons which are obvious to anyone who's ever used SOAP/WSDL/etc.

The common theme was seeing complexity and, especially, abstraction as a universal good rather than something with real costs and forgetting how important high-quality implementations are, particularly when you're relying on them to help with all of that complexity.

> The common theme was seeing complexity and, especially, abstraction as a universal good rather than something with real costs

Rich Hickey did a great service outlining some common problems when thinking about the word complexity itself: http://www.infoq.com/presentations/Simple-Made-Easy

I don't think it's about the engineers wanting to see complexity, so much as the problems you mention stemming from design-by-committee.

In what sense was the web built on "XML and Java"?

The long arc from "what came before" has periodically involved cleaning up old complexity. There have always been arguments about how simple is simple enough, but these systems weren't designed with complexity as a goal.

The web is a lot of things, but broad consumer adoption of web technology also involves boring things like banks. SOAP and WSDL weren't created in a vacuum. They exist because Java / XML made it even possible to bridge the gap from the old world.

I don't know what "old world" you're talking about. When the web was first a thing, it was written in C and PHP and Perl. All the Java crap was layered on top later, temporarily, and unsatisfactorily. The enterprise repeatedly misunderstands what the internet is and how to use it, but that is the enterprise's problem, no one else's.

Banks.

As much as we like all sorts of features of the web, integrating commerce was what brought the enterprise in, drove down costs, etc etc etc.