Safari 3 and 4 on the Same Mac? Yes You Can! (Maybe)
Maybe I should just get a T-shirt that says “Life is a giant beta” since I’m a sucker for any new application. Like so many others, I grabbed Safari 4 yesterday so I could kick the tires. The beta software kicked me back since it wiped out Safari 3 on my Mac. My usual trick of renaming the older application before installing the new one didn’t work this time. I probably should have known it wouldn’t, since Safari 4 updates the Webkit framework. (By the way: my rename trick works perfectly fine with Firefox 3 and 3.1b2 in case you want to run both versions.)
You can get back to Safari 3 by using the Safari 4 uninstall, rebooting and then downloading version 3.2.1 directly from Apple. If you do want both, perhaps this list of tricks from BeatnikPad will work for you. I haven’t tried it yet as I’m still smarting from the many installs, uninstalls and reboots just to get back to where I was when this fiasco started. 
From my perusal of the steps, the advice seems sound enough. You’ll have to run a few Terminal commands and use a Webkit nightly build for Safari 3.x but if all goes well, you should have a close facsimile Safari 3 and 4 on your Mac. As always with these types of problems, use the solution at your own risk. If my bruises heal quickly from getting back to status quo, I’ll give this a try and report back.
Wouldn’t you know, I just posted a much less intrusive way of doing this on my blog here: http://brian.mastenbrook.net/display/29 . It’s a little script that I whipped up to allow folks to try out the Safari 4 beta without running the installer at all, which means that Safari 3 continues to be installed as the default HTML renderer. The method given in the article you linked to installs Safari 4 systemwide, which means that other applications which use the WebKit engine for HTML rendering (such as Mail) would also use the new beta engine.
I downloaded this onto my Acer Aspire One ZG5, and i am debating on removing firefox! I am new to Safari on Windows, and I think it runs better than firefox. Its hard for me to say this being a “PC” kinda guy, but good job Apple!
Um, where can I get one of those T-Shirts. That is brilliant.
Glad I can uninstall 4 and put 3 back in if I need to. Thanks for the tip.
As for the beta thing, check out Life in Perpetual Beta. Melissa even has t-shirts.
I tried “Brian Mastenbrook” script (see his post here) and that works great, can recommend it!