As of Firefox 4.0 and newer it is Mac OSX 10.5+ and Intel that is required.

The last version from Mozilla to work on OSX 10.4 and also for PPC is Firefox 3.6.*

http://www.mozilla.com/en-US/firefox/all-older.html

There is also a third-party project for PPC users at http://www.floodgap.com/software/tenfourfox/ for Firefox 5.0 however the site has recently gone down.

THANK YOU!

I have the same problem, just want a version of Firefox 3.5 back. Where can I find that?

Firefox 3.5 is an antique version that is chock-full of security vulnerabilities.
Firefox 3.6 also contains security vulnerabilities; it stopped being supported on April 24.

• www.mozilla.org/security/known-vulnerabilities/

If you can't run the latest version because your system doesn't meet the requirements, it's highly recommended that you use another browser that is secure. TenFourFox is a third-party build of Firefox that is kept up-to-date and runs on Mac OS X 10.4 and PowerPC Macs (as a side note, I've never seen the site go down; whatever problems James noticed 9 months ago must've been a fluke).

• www.floodgap.com/software/tenfourfox/

If your system can run the latest version, but you want to downgrade because you've experienced problems, please start a new thread and someone will try to help you.

If you understand the security risks but want to downgrade anyway,

• Firefox 3.6: www.mozilla.com/firefox/all-older.html
• Firefox 3.5: ftp://archive.mozilla.org/pub/mozilla.org/firefox/releases/3.5.19/

OMG! Thank you so very much. I downloaded TenFour and all my bookmarks, my beloved Scrapbook are all intact. Thanks again and have a great day . . . I will!

Gingerbread Man ROCS!