Tabbed browsing was present in Windows browsers before Opera. There were a lot of browsers that just embedded IE's Trident engine, and some of them had tabbed b

Tabbed browsing was present in Windows browsers before Opera. There were a lot of browsers that just embedded IE's Trident engine, and some of them had tabbed browsing. Wikipedia says that the first was NetCaptor in 1997. It does sort of make sense that this happened on Windows, because tabs are a natural variation on MDI.