Both Safari and Mozilla have tabbed browsing, form auto-fill and password management. Mozilla is based on gecko, Safari on KHTML. I honestly cannot say which layout engine I prefer. I would say without a doubt both engines are better at standards compliance then the engine that Internet Exploder uses. I say this more as a web developer then a web user though. As a web user I don't care what the layout engine is, just as long as it makes the site look correct. The general user interface of both browsers are equal. It is nice to have a Search field to the right of the URL field in Safari. Although it is just a little different in Mozilla. You type the search term in the URL field, hit the down arrow, then hit enter. It is still really nice to have a dedicated field. The forms auto-fill feature of both Safari and Mozilla I find to be similar, and I see no differences in the two of them. Tabs In the tabs bar in Mozilla there is a button to the left to create a new tab. This is nice and but could be done with Command+T in either Safari or Mozilla. Sometimes I don't want to have to use the keyboard shortcut. The New Tab button is a nice touch Mozilla has. The innovations that Apple has put into Safari's tabs are really wonderful though. You can close a tab without going to it with the little 'x' on the left of the tab. On the right of the tab you see the status if the page is still loading, I really like this feature. Password Management Mozilla has a very nice Password Manager that shows all the stored passwords. Safari on the other hand uses Keychain Access. Either one is fine by me. There are however passwords that cannot be stored using Mozilla. These passwords can be stored using Safari. I do not understand why they can but they can. And that is what matters to me. The only innovation that Safari has to its own is the Snap Back feature. It is by far the best thing to happen to web browsing since tabbed browsing and, well, password management. Blocking images from a specific server is a nice touch that Mozilla has. Now if Mozilla could block SWF files from a server, that would be a killer feature. But still even without the ability to block ad banners I still use Safari as my main browser Mac OS X. I only open Mozilla or (gasp) Internet Exploder if I am forced to. On Windows I use Mozilla full time. I only open Internet Exploder if I am forced to, or I want to visit a site that has some Flash I want to look at.