htout
htout is an HTML generator written by Tim Bradshaw. It can be found at http://www.tfeb.org/lisp/hax.html#HTOUT. Here's some more info from Tim Bradshaw's website:

Lisp's syntax can be used to express the structure of SGML/XML-based documents very concisely:

<doc>
  <heading>Foo</heading>
  <para>this is a paragraph</para>
</doc>

Becomes

(:doc
 (:heading "<font color="#008b00">Foo</font>")
 (:para "<font color="#008b00">This is a paragraph</font>"))
  

Because Lisp is also a programming language it is possible to mingle Lisp code and SGML/XML markup in Lisp syntax to programmatically generate documents.

In order to do this `right' for XML you need to deal with issues of Unicode, case, namespaces and so on. But almost all documents don't need to worry about this complexity. This code provides a simple way to mix HTML markup with Lisp code. It does not enforce anything except the matching of tags, so it knows nothing about document types or anything like that. In fact the only thing you need to tell it is which elements have empty content models, so it generates <br> rather than <br></br>.