We have a section for overlay networks on the tunneling list[0] I maintain. This is a very interesting space with some excellent software.

I certainly have my gripes about the closed nature of Slack itself, in particular using a closed protocol when the model is clearly "federated" between multiple servers internally. That said, the contribution of something on the scale and quality of Nebula back to the open source community is hard to argue with.

[0]: https://github.com/anderspitman/awesome-tunneling#overlay-ne...