Limulus polyphemus is the Atlantic horseshoe crab.

Eric McCarthy

That’s me. I write software in Tucson, Arizona.

In March 2018, I got married!

My current hobby project is Penumbra, an implementation of The Ray Tracer Challenge that runs on the web.

My “professional” website is at


You may email me at or find me on ActivityPub social media at


Here are some other places I am actively putting stuff.

And here are some places where I have put stuff, but I am doing less of that now.