MultiZilla, an amazing success...

One of the great successes of Mozilla browsers, including Firefox, SeaMonkey and Flock has been the introduction of tabbed browsing. It wasn't always like that of course, and it was MultiZilla that introduced the concept to the Gecko world, back in 2000. And from that flying start we are still leading the way in terms of user choice and innovative features like pre-loading of (pref) panel, automatic tab selection and our all-in-one managers!

MultiZilla Achievements

Here's an overview of features that were first introduced by the MultiZilla project, all written by HJ van Rantwijk, which are later adopted by either the Mozilla Foundation or the Mozilla Corporation (and because of that others, like Flock and Microsoft as well).


  • Tabbed Browsing (top and bottom tabs)
  • Favicons on Tabs
  • Close buttons on Tabs
  • Drag and drop for Tabs (tab reordening)
  • Reopen Closed Tabs
  • Groupmarks (now obsolete)

Main Menu

  • New Tab (File menu)
  • Close Tab (File menu)
  • Full Screen (View menu)
  • Recently Closed Tabs (History menu)
  • Bookmark All Tabs (Bookmarks menu)
  • Clear private Data (Tools menu)

Popup Blocking

  • Popup Indicator in status bar
  • Options to open blocked windows


  • Automatic update checks
  • Extension Manager
  • about:config
  • Confirmation before quiting
  • Session Manager
  • Advanced Popup Blocker

Tab Context Menu

  • Menu option - "New Tab"
  • Menu option - "Reload Tab"
  • Menu option - "Reload All Tabs"
  • Menu option - "Close Other Tabs"
  • Menu option - "Bookmark This Tab"
  • Menu option - "Bookmark All Tabs..."
  • Menu option - "Close Tab"

Context Menu

  • Context menu protection
  • Menu option - "Open Link in New Tab"
  • Menu option - "Block images from ..."
  • Menu option - "Unblock images from ..."

Web Feeds

  • Indicator in status bar
  • Feed Viewer (preview)
  • Options to subscribe to feeds
  • Non of the formentioned features use our source code, but ideas.
  • Non of the formentioned features are written by us, but have been "looked at" by developers.
  • Some of the formentioned features where first considered to be "bloat", but they have all been assimilated by the Borg err... Mozilla.
  • Some features (for example the close button on tabs) were added, then removed and then added back again.