<p>CTY isn’t bad (the idea is sort of like EPGY, although the two programs are structured differently). Personally, I think EPGY is fine, although I’ve heard more about their summer programs than their online courses. But as I said, look around at any university’s website–[LSU[/url</a>], for example, seems to have a multidimensional calc class online, although I don’t know if that’s exactly what you’re looking for or if they accept high schoolers or how they handle the prerequisites. I’m sure there are others–see for example [url=<a href=“http://talk.collegeconfidential.com/parents-forum/547424-multivariable-calculus-line.html]this”>http://talk.collegeconfidential.com/parents-forum/547424-multivariable-calculus-line.html]this</a> thread](<a href=“http://www.is.lsu.edu/coursefactsheet.asp?nid=301&Rubric=MATH&CourseNr=2057&Version=O]LSU[/url”>http://www.is.lsu.edu/coursefactsheet.asp?nid=301&Rubric=MATH&CourseNr=2057&Version=O). Also, Shorter University in Georgia offers a course [online</a> at any time](<a href=“http://www.distancecalculus.com/multivariable/]online”>Multivariable Calculus Online Course for Credit - Distance Calculus) for credit, and I think they accept high schoolers (or anyone who pays). I can’t say whether it’s good or not, but you might want to look into that.</p>