Graphing Calculator was one of the delightfully “impossible” things I discovered in the hard disk of our brand new iMac back in 1998. I had just started using a TI-83+ at school, so seeing a 3D full-color animatable graphing calculator with a beautiful equation editor slotted directly into my brain as “this shouldn’t be possible! yet here it is!!” I have never found a real use for it, but always wish I could. I bought the iOS version when I found out about it to pay back the authors for my teen-aged delight.

The origin story is cool as heck, too. As discussed many many times on HN: http://pacifict.com/Story/