It's far from a fortune, and its future is uncertain, but I've been earning a bit via donations with my writing/podcasting for almost 20 years now: https://www.damninteresting.com

I'm also working on diversifying, starting with a free daily word game that I hope gets a little traction on Patreon: https://omiword.com

I have a few other projects-in-progress, if I'm lucky, one will earn a dollar or two.

I make Reflect with my partner. I do it on the side, they do it fully. It’s a private, local-first app to track and analyze your own personal data and run N=1 experiments.

https://apps.apple.com/us/app/reflect-track-anything/id64638...

I spun off geek-themed speed dating to geek themed singles mixers. They have party games, couch co-op and vs games, karaoke, and get-to-know-you games to encourage strangers to talk to each other. A drink is included with the ticket.

I buy and sell older electronic musical instruments mostly from the long tail.

It is a rationalization of my GAS, gives me an excuse to take things apart, provides the satisfactions of repair, creates an opportunity to learn new skills, and makes a little money.

I sell 3D printed paintball bunkers, useful for game planning before/during a tournament, https://pbminimaps.com.

I run a SaaS to help open-source devs monetize their GPL-licensed SDKs/libs. Going good so far.

I made a lil web game over the course of 5 years - https://syns.studio/more-ore.

Made around $3X,XXX so the returns aren't too good but it's something i'm passionate in.

I run an audiophile music recommendation newsletter. It pays peanuts, but it's just past breakeven less than a year in and it's fun.

For the curious: https://SeekHiFi.com

Investing most of the post-tax compensation from my main job in VTI, and leaving it there.