I love XSLT in theory. It had the daring to say that the most frequently programmed thing that we do is just translate data structures of one shape into data structures of a slightly different shape, and it said “That is what I shall focus on, doing just that.” And the way that it produced that, by “just start writing your output document and insert XSLT when you finally need to loop or query the input” seemed quite nice too, a sort of PHP dialect which didn't have to “escape” out of the document type and resort to echoing raw text.

There is a pure functional programming language waiting to be resurrected from the ashes of XSLT, following Haskell's original idea that a program is a pure function from a stream of inputs to a stream of commands. I just hope that someone removes the XML from it, to save on the pain of my pinkies mashing those greater-than and less-than signs. I like the abstract idea that XML is recursively embeddable, and even the radical suggestion that maybe XSLT should be involved in metaprogramming its own syntax trees, but I am not sure that this is worth it. Maybe if we blur the lines between our code editor and a generic UI, someday?