I'm surprised no-one mentioned SXML, Kiselyov's representation of XML in Scheme. His paper, "A better XML parser through functional programming", can be found here: http://okmij.org/ftp/papers/XML-parsing.ps.gz.
The introduction covers the difficulty of parsing XML fairly well, which is another way of saying that XML does have a fairly complex "model" behind it that Lispers often ignore.
The introduction covers the difficulty of parsing XML fairly well, which is another way of saying that XML does have a fairly complex "model" behind it that Lispers often ignore.