Originally Posted by Virgil-TB2
I'm surprised they didn't add multiple processes for tabs also, since it would be pretty easy to do.
Says the self-confessed non-developer. If you want gain some insight into trying to retrofit a mostly single-threaded architecture into a multi-process one I urge you to read the Firefox development mailing lists where the Mozilla developers are experimenting with exactly that problem. Hint: It's far from trivial, especially when having to do it on multiple platforms.
However, there is actually lots of new sandboxing on Safari 4, just nothing to do with the tabs.
Too bad Apple is again after a quick money grab and made it a 10.6 only feature despite Chrome being a working proof-of-concept that sandboxing works on 10.5 just fine with the OS tools available.
Anyway, I'm glad that Apple *finally* fixed the ridiculous memory usage. Safari still uses about 300-400 MB memory (give or take 20) but at least it *stays* in that range even after extended use. My best guess is that the fixed amount of used memory is used for caching the site previews in top sites/history search and indices for full-text search.
I'm really disappointed that Apple didn't implement the non-modal password dialogue from Firefox/Chrome as it's such an *obvious* usability improvement while they wasted time experimenting with tabs-on-top.
It's also a little bit disappointing that the adress bar does not work like Firefox' aweseome bar. You still can't search for arbitrary substrings in the URL/site title. It's pretty much the same old adress bar as in Safari 3 with a much improved result field.
Top-sites are slow to load and are in dire need of speed optimizations. I wouldn't be surprised if Apple tackles the problem in of the subsequent releases.
Altogether this is a very solid release though, it just lacks any kind of ambition.