Got an email from Saeid Nourian this morning extolling the wonders of his 3D Graphing Calculator, so I thought I'd give it a try. It is not an online tool, it is an actual application program that you have to download and install on your computer. But I took a chance and downloaded and installed it. I tried a couple of simple minded equations and it seems to work and my computer hasn't blown up, so maybe it's okay. It comes in three flavors for Windows, Apple and, surprise, surprise, Linux, which is what I needed. It also comes at three price points: free-try-it-for-30-days, economy and full-boat professional. Now all I need is a problem to try it on.
Saeid works for the Concord Consortium, which seems to be doing some interesting things with computers in education.