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

Try http://www.mozilla.org/en-US/firefox/all-older.html that is currently making 3.6.24 available

Note firefox 3.6 may not be supported for much longer, but older and unsupported versions are (at least up until now - may be some changes with fast release cycle) still made available for download from elsewhere within the Mozilla sites for testing and development work.

Other versions available as mentioned, from official site, but I would rather not post the exact address info in a popular search engine indexed thread. Will pm link

Thanks!

Any idea where I can find version 4.0? I also need that version as well.

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

ftp://ftp.mozilla.org/pub/firefox/releases/4.0.1/

Thanks! I looked for it on filehippo but was not seeing it :)

I have compiled a list of older Firefox versions on this Firefox Review web page. The links are from the official Firefox website for Windows (US-English version) - versions 3.6.24 to 7.0.1. However, please note that Firefox recommends using the latest stable release version because earlier versions may have security and safety vulnerabilities.