Firefox (or the Mozilla browser that became Firefox) gave us our modern idea of tabbed browsing. If I remember correctly, it was initially an experimental feat

Firefox (or the Mozilla browser that became Firefox) gave us our modern idea of tabbed browsing. If I remember correctly, it was initially an experimental feature buried in the settings, but it quickly became a popular mainstream feature that Safari and IE adopted. Opera had an earlier version of tabbed browsing, but it was tacked on to their existing Windows MDI interface. In the 90s, MS Visual Studio 6 had a 3rd-party plug-in that would add tabs to their existing MDI interface. Borland's Delphi and C++ Builder may have been the first apps to provide a true tab-based document handling in the early-mid 90s.