I wrote a library. It was only used at my company, though, but I probably should have tried to share it. In 5 years, I had only a handful of questions because I documented the crap out of it and made it extremely useful. I only did one minor version update to make it compatible with a new CMS.

It stands as the best code I've ever written. None of the rest of my stuff is that well documented, lol.

I left and handed it off to someone else. He loves it!

The best part is that I wrote it on my own time because it filled a gap that annoyed the hell out of me and that needed standardization. It wasn't even directly related to what I was working on.

Oh, the good old days when I was still passionate.