> Gitea support actions like GitHub's

Citation needed. nektos/act is for sure not "like GitHub's"

Here's Gitea's own comparison to GitHub's Actions: https://docs.gitea.com/usage/actions/comparison

Sure, it's not identical, and no one claims it is. I think it's defensibly like them, though.

Yes it is. It's not identical, but it is "like" it.

Most of my build config run on either platform (Gitea and Github) interchangeably.

We've run Gitea actions (and contributed here and there) for a couple of years, since-by-side with Github. We host in containers on the Gitea side so there are some marginal differences as to what can be run in a job, but our experience has been very positive.

> You can have a nice CI/CD pipeline that runs 100% in-house, for free.

Interested! Some detail on how you achieve this for free would be great.

Well, Forgejo’s Actions are very similar to GitHub’s: https://forgejo.org/docs/latest/user/actions/actions/

If you want to run a process after each push to a branch or merge into main or whatever, you describe it in a YAML file in that repo. Configure some workers to run those actions and off you go! I use it for things like running tests and applying Terraform changes.

I understand that part. Mostly interested where the runners are coming from? macOS especially is pretty costly to provide runners for, so who is doing that for free?

You provide the runners on your own hardware. Perhaps a Mac mini would fit the bill?