Executing Gummiworms The trials and tribulations of a grumpy curmudgeonly old git

Hunter Davis has open sourced QuickGrapher

Hunter Davis, no relation (AFAWK) has made QuickGrapher, an HTML5 Equation Solver & Grapher Open Source. He's placed the source on github and in less than a week someone has ported it to Android. I messed around with the beta about a year ago and was really impressed.

Hunter has also Open Sourced another of his projects as well. Source Tree Visualizer which basically turns your source code tree into a real tree  in a pretty landscape

You can find Hunter's post about QuickGrapher here

and his post on SOurce Tree Visualizer here

Even if these two things don't appeal to you Hunter's blog is always a pretty good read.