TidyTabs Personal Edition – The Portable Freeware Collection ⋆ FGR* Blog
TidyTabs enables you to add up to three tabs to any application window. You can group multiple programs into a single window and then switch between them using tabs. Tabs appear when you hover your mouse over the top left corner of the window. To group the application with another window, simply drag its tab onto the other windows tab bar and create a tabbed group. The program can exclude or allow specific programs.
A pro version includes multi-monitor support, the ability to reorder/rename tabs and is not restricted to three tabs per group.
Functional in 64-bit.