Interesting twofer from Jim Waldo, who is one of the Really Smart Guys in the Sun software ecosystem. Way back in May, he wrote Going all in..., arguing that when sending data over the wire, it’s good to send objects, and that trying to send raw data, not governed by the semantics of any particular object system, is problematic. I’m OK with sending objects over the wire—as long as they’re short-lived and you keep those fallacies in view—and the problems Jim outlines are real. But in fact, the basic value proposition of XML is that it allows you to receive data from another program while insulating you radically from the other program’s choice of computer, operating system, programming language, database, and so. And, it seems to work in lots of places, for example syndication feeds and product lookup. This doesn’t mean it’s easy, or that it works everywhere, but there are existence proofs. So I wrote a quick note to Jim along the lines of “Uh, what about XML?” Now I’m feeling guilty, because I see from his latest, What is XML?, that the question kind of derailed his plans for what he was going to write about and, well, now it’s October. Anyhow, go read the piece, it’s a good one, worth waiting for. To Jim’s points, I’d also add that pushing the syntax problem down into XML buys you both Unicode goodness and access to a whole raft of good free parsing software, which are not to be sneezed at. But his analogy between XML and Unix pipe-fitting culture is sound. Also, like Jim says, XML doesn’t make the hard problem—What does this character string mean?—go away.
