In order to share workspaces and files with other people, or to be invited to other people's workspaces, you need to add that person to your contacts list.
Anyone who is a member of the 3dSwYm community can be added to your contacts list. You can also invite people to join the 3dSwYm community via email from within the n!Fuze add-in. When you add someone to your contacts list, you are automatically added to their list. In this way you can quickly build a network of mutual contacts.