Some of the suggested links seem to not be maintained

[jackiekazil]

Not sure how I arrived here, but I did. I enjoyed this list.
It seems like some of the projects aren't being maintained.

Assuming this list is actively being maintain, I would suggest creating a standard for what is being considered an active project and what is not.

For example: Plaitpy https://github.com/plaitpy/plaitpy hasn't been updated in 6 years. It also has four tickets and the last ticket was created in 2020. This seems like an obvious "not being maintained," but I know other projects may be more nuanced.

I will a submit a PR to remove Plaitpy, but would love to see an explicit definition.