Joined the #dreamgrid #mewe. Dreamgrid is a DIY #opensim server that supports a smart 300-region grid. As I understand it, regions are only active when there's an avatar in them so server requirements are manageable.

Of interest as it would potentially accommodate larger scale railway models.

There's also a separate opensim Transport MeWe where Laura Ess has an awesome project to model and script railway infrastructure at a more detailed level than I've dared attempt.