I am familiar with both Leo and Elucidative Programming (although not the Elucidator project).
They each drift a little bit further from my interpretation of Knuth's LP concept than I wanted to go.
With Leo, the outline is nice (and in fact the tool I'm developing will include a Leo like outline view),
but it just isn't  full on LP. I didn't sense that it had a user base that made it the right choice as a
starting point. The outline view is actually a rather easy view to generate. The folded view as I'm conceiving
it is quite different (and was/is the most intellectually challenging/interesting part of what I'm doing).
Likewise, Elucidative programming separates the code view and the documentation view, but links them together so
you can easily move back and forth. To me this is again a big move away from Knuth's concept where the code
and documentation are intertwined.

I'm very much concerned about creating just "yet another" LP tool. I'm trying to make sure I learn from what others
have done, but I didn't see either of these as having important ingredients that I wanted to build on (but I could easily
be wrong).

The folding idea I am implementing it not new, even in the LP literature (although I wasn't aware of this comment
when I conceived off the idea). It was proposed in 1986. Thimbleby observed
(Thimbleby, H., Experiences of literate programming using cweb (a variant of Knuth's WEB). Computer Journal, 1986. 29(3): p. 201-11)
that one “of the disadvantages of literate programming … is that the programmer cannot view the code of macro bodies in situ at the point of invocation.” He goes on to propose “an interactive version” in which the programmer “would press a button and an invocation would unfold into a (name, body) window in position.”

I completely agree that it would be great to agree on a DTD. I'd be quite happy to adopt anything reasonable.
That is a simple minor change to the input parsing and save operations.

Charlie McDowell, Professor                     (831) 459-4772 (w)
Computer Science Department                     (831) 427-2076 (h)
University of California                        (831) 459-4829 (fax)
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