I've just finished setting up my calculus course for the coming spring quarter, using my interface scripts with WeBWorK, the symbolic math. homework generator and grader. A couple of the problems further link to WIMS, another such system (c.f. Problem 8 in Practice Hmwk 0). You can log into my course at https://webwork.math.ohio-state.edu/moodle/ as a guest without an enrollment key.
Martin, feel free to link to my site from your list of Moodle sites.
A couple of general comments about things I'd like to see improved in Moodle, from my limited experience in using it. First of all I am using a course format which is intermediate between the topics and weekly format. It's basically a weekly format, except that the units are not necessarily covered over a one week period - sometimes a week and a half or two weeks.
I will probably hack Moodle to implement the following minor changes. I prefer "Course Outline" to "Topics Outline" as the header for the main course page. Also in my use, Assignments are really Assessments. Unfortunately Resources are too large of a grab-bag category, and the subset of "Program Resources" are really "Assignments" in my usage.
Also my course is divided into 6 problem sections. I want to have a field in Moodle to indicate which section each student belongs to. The only way I could find to do this was to create a bogus Assignment to contain this data as a "grade". Also I would like to be able to sort on this field.
Finally I noticed today that on Martin's site, Moodle refused to display the list of participants since the list contained more than 500 members. I am worried about what other such limitations might be built into Moodle.
Zig Fiedorowicz