What is the longest running side project that you still work on?

http://nymph.io/

This project technically started in 2009, as part of another project called Dandelion (which then was renamed to Pines), then around 2014 I pulled it out into its own project, Nymph. I worked on it on and off, until 2021, when I rewrote it for Node.js as Nymph.js.

It now runs my email service, https://port87.com/

Here's the oldest code I can find on GitHub from July 7, 2009:

https://github.com/sciactive/pines-components/blob/144ce877e1ec9af7fa34c8eb8b11aeb7ae0efb5e/com_entity/common.php

And here's the first version as its own project from Sep 8, 2014:

https://github.com/sciactive/nymph/tree/fdf5f770da7e5acc6938debbaeb8c09cfd080e15/src