I have just recently launched the alpha version of my app:
http://ezlearnz.com
There are still major pieces of functionality missing, e.g. anything that has to do with user profiles, comments, voting, and other things. I'll be implementing them in the coming weeks/months. But before I do so, I will eat my dogfood and create some lessons/courses.
Please be gentle in your (constructive) criticism; I was an absolute newbie when I got this idea ~9 months ago, so I had to learn html, css, a bit of javascript, and ruby on rails in order to make the app. Incidentally, I'm looking for a co-founder.
Thanks for your feedback!
1. The site requires me to have my browser window full screened at 1280x1024 resolution, otherwise it forces me to scroll horizontally.
2. The top of the site is wasted.
3. It looks strange to me for the background color to extend in to the main "content area" -- maybe consider making the background in the middle all the same color.
Beyond that... The site doesn't really tell me what it does, you should give me some more info, and don't assume that I know what SourceForge is, although I think Wikipedia is widespread enough to use that reference.
"try it out! In the left column..." -- the left column, immediately below that, is your Features image with the pic of the kid.
The "comment on this" link doesn't seem to do anything, neither does "vote on this" or "revision history." I click it and get a busy mouse cursor for a second, but nothing actually happens.
Whenever I saw a link to a quiz or test, it just takes me to a set of blank rich text input boxes. I don't see any questions or a way to submit what I assume are answers.
When editing a subject, I don't see any way to rearrange the Lessons. Drag and drop, ajax style, would be nice for that, in addition to an integer value for the position.
Beyond the usability stuff, I'm not sure how much sense it really makes for anyone to be able to edit the courses. It seems like only the teacher should be allowed to do that, as the teacher should be an expert in his field and should not need to have his lesson plan corrected in the middle of a "semester."
All in all, it looks like you've got an interesting concept there. One possible use I can see for the technology is that, once you get some courses on there that are proven to be correct, you could export the whole course, or a set of courses, to CD and sell or donate them to developing nations. You might even be able to partner with the XO and other laptops aimed for kids who might not have access to quality education.
You also will eventually need to get teachers to create lesson plans on the site. I think a good way to do that would be to approach private schools and sell them on the benefits of having that info online -- the parents can see exactly what their kids are studying, the teachers, if they're any good, will feel good because they're able to teach more kids than just those who sit in front of them, the school can get some philanthropic benefits out of it, etc.