1. select one or more project and use the ‘Export’ context menu or File > Export. Here I select General > Archive File: Export Project as Archive File
2. In the ext dialog deselect files and folder. Additionally need to specify the archive file. Uuse Filter Types(e.g. to include *.c and *.h), but really what I wish is that this dialog would consider the ‘derived’ flags for files and folder, so deselect them easier. Archive File Settings
3. In the destination workspace, Use the menu File > Import: Import Dialog to Import a Project
And here is the stumbling point: don’t (!) select ‘Archive File’, but ‘Existing projects into Workspace‘. Yes, We exported it as Archive File, but Importing an Archive File is importing an archive file inside a project, not (!) as a project. Yes, this is a usability quirk in Eclipse.
4. In the next dialog choose the archive file and make adjustments which project want to import. Note that it will automatically copy the projects into my workspace. Import Archive Projects
5. Pressing Finish, and my projects get imported.