I had a look at the message you refer to. It is a good summary, and in line with what I thought was straightforwardly do-able. I haven't uploaded any of my problems to STACK yet but that's how I imagined it going: cutting and pasting like you say. In the long run I'd like to be able to export to Moodle XML, then automatically upload the XML to the Moodle site.

I have been making use of tex1 and texput in Maxima to generate LaTeX. It is alarming to me that they may not be supported by default in Moodle/STACK. I decided to do most of the LaTeX generation in Maxima instead of writing the LaTeX and filling in the values of variables because of situations like the following: If Maxima has a0:-3 and I write LaTeX \(x-{@a@}\) I will get \(x- -3\) which is exactly what I asked for but unconventional. If I define Maxima output0:tex1(x-a0), Maxima will do the algebra and LaTeX \({@output0@}\) will be \(x+3\) as we would normally expect. Lots of little things like that made me prefer assembling expressions in Maxima and exporting them whole hog instead of one bit at a time.

Some more thought will have to be given to how to create the grading trees. I'm sure it's documented somewhere but I'll probably just create a question with some complicated grading trees and export it from Moodle to see what the XML looks like. I think I won't go there for now because the Maxima fragments on the grading side run in the same session as the Maxima initialization on the question side in STACK, but that is rather awkward to fake in Org until there is a session capability in the Maxima blocks, I think. So it might be possible to write the grading trees in Org but would be difficult to test them.

There is no export from Moodle to XML but there are external packages that will do it ... with what quality, I don't know. But once the Org file is in "Org XML" it should be relatively straightforward to transform it to the XML required by Moodle using XSLT or whatever. Lots of details, but that's my big picture strategy. I'd like eventually to export directly from Org to Moodle XML but that's currently beyond my skill set.

I posted my kludge to work around the lack of sessions to https://github.com/edoolittle/org-moodle. It's pretty ugly but works for now.

Again, the work to sessionize Maxima is probably straightforward but lots of details that are currently beyond my skill set. I am not proficient at Emacs Lisp. For now I'm concentrating on the low-hanging fruit that I can do quickly.

I have avoided for now using the Maxima "plot" command. Actually, it's "plot2d" in Maxima/Org and "plot" in Maxima/STACK. Note they are two slightly different things, which means that one must always be conscious of the context and not use any of the nicer "plot2d" features when writing questions that will eventually find their way into Moodle/STACK.

Also "plot" is just too restrictive in some cases. I can graph two curves (parametric curves even) and put dots at their intersection points but I can't figure out how to label those dots. Which is A and which is B? So even though I've used it in the past, I think I'd rather put my energy into figuring out how to generate diagrams with JSXgraph which is modern, sophisticated, and beautiful compared to plot. A difficulty is how to get the {#maxima-variable#} out of the maxima results and into the JSXgraph block. I /think/ that's just a minor issue with noweb.

I think an emulator is a bridge too far for now. What I want to do is run Maxima blocks to get a paper version of the exam with an answer key (for graders) and complete solutions (as an "exam wrapper" to return to the students with their graded exams so they can learn from the correct answers). Both questions and answers will have to be generated (the variable parts anyway) by Maxima because I want the capability to generate multiple different paper versions of any question/exam, perhaps even one version of the exam per student. Then for versatility I want the questions to be in a form that can at least be cut-and-pasted into Moodle, so I can use last year's exam questions as this year's problem set questions. With some tweaks, I hope to eventually automate the procedure of getting the questions into Moodle. The hurdles are correct XML format, grading tree, "publishing" process to include correct image files, the whole randomization and quality control subsystem (what STACK calls "deployment of variants"). I don't know how the latter can be made sense of in Org Mode. Even things like the random number seeds that index different variants might be interpreted differently in Org and STACK, breaking the connection between Org and STACK variants of a question. So lots of work to do.