Is there an open-source alternative to the Dev Containers extension?

[schuelermine]

Specifically, this one: https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers (ms-vscode-remote.remote-containers)

There is an open-source CLI for spinning up these containers but not for connecting VSCodium to them.

[schuelermine]

Or, I guess, more generally, an extension to connect to containers (without SSH). Making the containers seems to be possible with the CLI… unless the extension would need to inject something into the container spec on build.