[throwawayForMe2]

I did commercial team Smalltalk development using the Digitalk toolset, for a team of around 16 people.

You start with a base development image, loaded with the toolset and frameworks for the project. No one modifies this image.

You share the app code through a source control tool. We used Team/V. Start up the project base image, open the repository browser, load the project packages. Make changes, commit source back to the repository. No saving of the image for development.

So shared, but never changed base image for the project, and app code sharing through the source control repository.