activeCollab lets you add users to multiple projects at once, a feature that can come in especially handy when someone new joins your team.

To do this, simply go to the user's Profile Page and from the Options drop-down select the Add to Projects option, as shown in the following screenshot:

On the newly-opened page, select the projects that you would like to add the user to and their Project Role or set of custom permissions that they should have). After you have set everything up, click the Submit button, and they will be assigned to all of the projects that you have selected.