An active project is the project you are currently working with. It appears in bold text in the workspace pane. The functions of the toolbar, utility bar, and menu items apply only to the project that is active.
To set the active project either
Right-click the project name in the workspace pane and click Set As Active Project.
Click Set Active on the Project menu and select the project name in the Active Project dialog box.
Press Ctrl+T and select the project name in the Active Project dialog box.