In order to interact with the information inside of Katana, it is almost required that users have two monitors so that they can have all of their tabs open simultaneously. This problem is further compounded as developers create new tools/plugins for artists which add more tabs, that the user then has to budget into their increasingly precious screen real estate.
However, the user only needs to be access one tab at a time, and many times, that tab only has a few options of tabs that it is eligible to interact with. A good example of this is the Scene Graph Tab, and the Parameters Tab. If a user is accessing the Scene Graph Tab, there is a very high probability that they will need to access the parameters tab.
Popup Tabs is designed to take advantage of this paradigm in hopes to resolve the screen real estate issue that has been plaguing computer graphics applications for decades. At its core, it is designed to allow users to take control of the GUI and how they interact with information. It does this by allowing them to create their custom interfaces by combining multiple tabs into one. This allows them to more easily access the information that is relevant to the task that they are currently working on.
Disclaimer: This is my own personal project and does not reflect the work of my current employer (Foundry)