In the second step of the OSGi Tutorial, Workspace Setup, the perfom action opens the preferences dialog where the target platform can be specified.

When I decided to go back to look at this, I realized that I had no idea how to open this dialog myself. My first guess, the project properties, was wrong. Turns out it was the Window | Preferences. You need to tell the user this. A new user, especially, will have no way of knowing this.

Also, this means that the preference is for all projects. When I specify a server it is on a project basis. Not all projects have the same preferences. Why is the target platform not on a project basis?