NetBeans has a feature called project groups which should provide you what you're looking for.
If you right-click on the Projects pane and select Project Group, there is a menu option called New Project Group... which will allow you to create a new group.
There are multiple ways to define a project group:
- You can create a "Free Group" that is either initially empty or based off of your currently open projects. You can manually add or remove projects from this group later, as needed.
- You can create a group around a "Master Project", which will include that project and all the projects that it depends upon
- You can create a group around a folder on disk, which will include any projects that NetBeans finds within that folder.
Eclipse has a similar feature, called "Working Sets", which provides the same functionality. I'm not sure what Xcode has to manage this, and with Visual Studio you just open a new copy for each solution you want to work with.