{
  lib,
  stdenv,
  fetchurl,
  libxml2,
}:

stdenv.mkDerivation {
  pname = "xhtml1";
  version = "unstable-2002-08-01";

  src = fetchurl {
    url = "https://www.w3.org/TR/xhtml1/xhtml1.tgz";
    sha256 = "0rr0d89i0z75qvjbm8il93bippx09hbmjwy0y2sj44n9np69x3hl";
  };

  nativeBuildInputs = [ libxml2 ];

  installPhase = ''
    mkdir -p $out/xml/dtd/xhtml1
    cp DTD/*.ent DTD/*.dtd $out/xml/dtd/xhtml1

    # Generate an XML catalog.
    cat=$out/xml/dtd/xhtml1/catalog.xml
    xmlcatalog --noout --create $cat
    grep PUBLIC DTD/*.soc | while read x; do
        eval a=($x)
        xmlcatalog --noout --add public "''${a[1]}" "''${a[2]}" $cat
    done
  ''; # */

  meta = {
    homepage = "https://www.w3.org/TR/xhtml1/";
    description = "DTDs for XHTML 1.0, the Extensible HyperText Markup Language";
    platforms = lib.platforms.unix;
  };
}